Sample records for lithography mask defects

  1. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    light, opens the way to future generations of smaller, faster, and cheaper semiconductors. EUV lithography relies on specialized lenses made of curved mirrors with...

  2. Reflective masks for extreme ultraviolet lithography

    SciTech Connect (OSTI)

    Nguyen, Khanh Bao

    1994-05-01T23:59:59.000Z

    Extreme ultraviolet lithographic masks are made by patterning multilayer reflective coatings with high normal incidence reflectivity. Masks can be patterned by depositing a patterned absorber layer above the coating or by etching the pattern directly into the coating itself. Electromagnetic simulations showed that absorber-overlayer masks have superior imaging characteristics over etched masks (less sensitive to incident angles and pattern profiles). In an EUVL absorber overlayer mask, defects can occur in the mask substrate, reflective coating, and absorber pattern. Electromagnetic simulations showed that substrate defects cause the most severe image degradation. A printability study of substrate defects for absorber overlayer masks showed that printability of 25 nm high substrate defects are comparable to defects in optical lithography. Simulations also indicated that the manner in which the defects are covered by multilayer reflective coatings can affect printability. Coverage profiles that result in large lateral spreading of defect geometries amplify the printability of the defects by increasing their effective sizes. Coverage profiles of Mo/Si coatings deposited above defects were studied by atomic force microscopy and TEM. Results showed that lateral spread of defect geometry is proportional to height. Undercut at defect also increases the lateral spread. Reductions in defect heights were observed for 0.15 {mu}m wide defect lines. A long-term study of Mo/Si coating reflectivity revealed that Mo/Si coatings with Mo as the top layer suffer significant reductions in reflectivity over time due to oxidation.

  3. Inspection of lithographic mask blanks for defects

    DOE Patents [OSTI]

    Sommargren, Gary E. (Santa Cruz, CA)

    2001-01-01T23:59:59.000Z

    A visible light method for detecting sub-100 nm size defects on mask blanks used for lithography. By using optical heterodyne techniques, detection of the scattered light can be significantly enhanced as compared to standard intensity detection methods. The invention is useful in the inspection of super-polished surfaces for isolated surface defects or particulate contamination and in the inspection of lithographic mask or reticle blanks for surface defects or bulk defects or for surface particulate contamination.

  4. Method and apparatus for inspecting reflection masks for defects

    DOE Patents [OSTI]

    Bokor, Jeffrey (Oakland, CA); Lin, Yun (Berkeley, CA)

    2003-04-29T23:59:59.000Z

    An at-wavelength system for extreme ultraviolet lithography mask blank defect detection is provided. When a focused beam of wavelength 13 nm is incident on a defective region of a mask blank, three possible phenomena can occur. The defect will induce an intensity reduction in the specularly reflected beam, scatter incoming photons into an off-specular direction, and change the amplitude and phase of the electric field at the surface which can be monitored through the change in the photoemission current. The magnitude of these changes will depend on the incident beam size, and the nature, extent and size of the defect. Inspection of the mask blank is performed by scanning the mask blank with 13 nm light focused to a spot a few .mu.m in diameter, while measuring the reflected beam intensity (bright field detection), the scattered beam intensity (dark-field detection) and/or the change in the photoemission current.

  5. Method for mask repair using defect compensation

    DOE Patents [OSTI]

    Sweeney, Donald W. (San Ramon, CA); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2001-01-01T23:59:59.000Z

    A method for repair of amplitude and/or phase defects in lithographic masks. The method involves modifying or altering a portion of the absorber pattern on the surface of the mask blank proximate to the mask defect to compensate for the local disturbance (amplitude or phase) of the optical field due to the defect.

  6. Thermal management of masks for deep x-ray lithography.

    SciTech Connect (OSTI)

    Khounsary, A.; Chojnowski, D.; Mancini, D.C.; Lai, B.; Dejus, R.

    1997-11-18T23:59:59.000Z

    This paper addresses some options and techniques in the thermal management of masks used in deep x-ray lithography. The x-ray masks are thin plates made of low-atomic-number materials on which a patterned thin film of a high-atomic-number metal has been deposited. When they are exposed to an x-ray beam, part of the radiation is transmitted to replicate the pattern on a downstream photoresist, and the remainder is absorbed in the mask in the form of heat. This heat load can cause deformation of the mask and thus image distortion in the lithography process. The mask geometry considered in the present study is 100 mm x 100 mm in area, and about 0.1 to 2 mm thick. The incident radiation is a bending magnet x-ray beam having a footprint of 60 mm x 4 mm at the mask. The mask is scanned vertically about {+-} 30 mm so that a 60 mm x 60 mm area is exposed. the maximum absorbed heat load in the mask is 80 W, which is significantly greater than a few watts encountered in previous systems. In this paper, cooling techniques, substrate material selection, transient and steady state thermal and structural behavior, and other thermo-mechanical aspects of mask design are discussed. It is shown that, while diamond and graphite remain attractive candidates, at present beryllium is a more suitable material for this purpose and, when properly cooled, can provide the necessary dimensional tolerance.

  7. Extreme ultraviolet mask substrate surface roughness effects on lithography patterning

    SciTech Connect (OSTI)

    George, Simi; Naulleau, Patrick; Salmassi, Farhad; Mochi, Iacopo; Gullikson, Eric; Goldberg, Kenneth; Anderson, Erik

    2010-06-21T23:59:59.000Z

    In extreme ultraviolet lithography exposure systems, mask substrate roughness induced scatter contributes to LER at the image plane. In this paper, the impact of mask substrate roughness on image plane speckle is explicitly evaluated. A programmed roughness mask was used to study the correlation between mask roughness metrics and wafer plane aerial image inspection. We find that the roughness measurements by top surface topography profile do not provide complete information on the scatter related speckle that leads to LER at the image plane. We suggest at wavelength characterization by imaging and/or scatter measurements into different frequencies as an alternative for a more comprehensive metrology of the mask substrate/multilayer roughness effects.

  8. Vitreous carbon mask substrate for X-ray lithography

    DOE Patents [OSTI]

    Aigeldinger, Georg (Livermore, CA); Skala, Dawn M. (Fremont, CA); Griffiths, Stewart K. (Livermore, CA); Talin, Albert Alec (Livermore, CA); Losey, Matthew W. (Livermore, CA); Yang, Chu-Yeu Peter (Dublin, CA)

    2009-10-27T23:59:59.000Z

    The present invention is directed to the use of vitreous carbon as a substrate material for providing masks for X-ray lithography. The new substrate also enables a small thickness of the mask absorber used to pattern the resist, and this enables improved mask accuracy. An alternative embodiment comprised the use of vitreous carbon as a LIGA substrate wherein the VC wafer blank is etched in a reactive ion plasma after which an X-ray resist is bonded. This surface treatment provides a surface enabling good adhesion of the X-ray photoresist and subsequent nucleation and adhesion of the electrodeposited metal for LIGA mold-making while the VC substrate practically eliminates secondary radiation effects that lead to delamination of the X-ray resist form the substrate, the loss of isolated resist features, and the formation of a resist layer adjacent to the substrate that is insoluble in the developer.

  9. An EUV Fresnel zoneplate mask-imaging microscope for lithography generations reaching 8 nm

    E-Print Network [OSTI]

    An EUV Fresnel zoneplate mask-imaging microscope for lithography generations reaching 8 nm Kenneth lithography design rules. The proposed microscope features an array of user-selectable Fresnel zoneplate-EUV, Fresnel zoneplate microscope, the AIT has been in the vanguard of high-resolution EUV mask imaging

  10. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with SEMATECH, an international semiconductor industry consortium, to create a unique Fresnel zone-plate microscope on Advanced Light Source Beamline 11.3.2 called the SEMATECH...

  11. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes | NationalCurriculum Introduction toLucas

  12. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes | NationalCurriculum Introduction toLucasInvestigating Extreme

  13. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergyBPA-Film-Collection Sign

  14. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergyBPA-Film-Collection SignInvestigating Extreme

  15. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergyBPA-Film-Collection SignInvestigating

  16. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergyBPA-Film-Collection

  17. Investigating Extreme Ultraviolet Lithography Mask Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergyBPA-Film-CollectionInvestigating Extreme

  18. Energy flow in light-coupling masks for lensless optical lithography

    E-Print Network [OSTI]

    Floreano, Dario

    Energy flow in light-coupling masks for lensless optical lithography Olivier J. F. Martin@zurich.ibm.com Abstract: We illustrate the propagation of light in a new type of coupling mask for lensless optical. Biebuck, B. Michel, O.J.F. Martin and N.B. Piller, "Light-coupling masks: an alternative, lensless

  19. Quantitative evaluation of mask phase defects from through-focus EUV aerial images

    SciTech Connect (OSTI)

    Mochi, Iacopo; Yamazoe, Kenji; Neureuther, Andrew; Goldberg, Kenneth A.

    2011-02-21T23:59:59.000Z

    Mask defects inspection and imaging is one of the most important issues for any pattern transfer lithography technology. This is especially true for EUV lithography where the wavelength-specific properties of masks and defects necessitate actinic inspection for a faithful prediction of defect printability and repair performance. In this paper we will present a technique to obtain a quantitative characterization of mask phase defects from EUV aerial images. We apply this technique to measure the aerial image phase of native defects on a blank mask, measured with the SEMATECH Berkeley Actinic Inspection Tool (AIT) an EUV zoneplate microscope that operates at Lawrence Berkeley National Laboratory. The measured phase is compared with predictions made from AFM top-surface measurements of those defects. While amplitude defects are usually easy to recognize and quantify with standard inspection techniques like scanning electron microscopy (SEM), defects or structures that have a phase component can be much more challenging to inspect. A phase defect can originate from the substrate or from any level of the multilayer. In both cases its effect on the reflected field is not directly related to the local topography of the mask surface, but depends on the deformation of the multilayer structure. Using the AIT, we have previously showed that EUV inspection provides a faithful and reliable way to predict the appearance of mask defect on the printed wafer; but to obtain a complete characterization of the defect we need to evaluate quantitatively its phase component. While aerial imaging doesn't provide a direct measurement of the phase of the object, this information is encoded in the through focus evolution of the image intensity distribution. Recently we developed a technique that allows us to extract the complex amplitude of EUV mask defects using two aerial images from different focal planes. The method for the phase reconstruction is derived from the Gerchberg-Saxton (GS) algorithm, an iterative method that can be used to reconstruct phase and amplitude of an object from the intensity distributions in the image and in the pupil plane. The GS algorithm is equivalent to a two-parameter optimization problem and it needs exactly two constraints to be solved, namely two intensity distributions in different focal planes. In some formulations, adding any other constraint would result in an ill posed problem. On the other hand, the solution's stability and convergence time can both be improved using more information. We modified our complex amplitude reconstruction algorithm to use an arbitrary number of through focus images and we compared its performance with the previous version in terms of convergence speed, robustness and accuracy. We have demonstrated the phase-reconstruction method on native, mask-blank phase defects and compared the results with phase-predictions made from AFM data collected before and after the multilayer deposition. The method and the current results could be extremely useful for improving the modeling and understanding of native phase defects, their detectability, and their printability.

  20. Commissioning a new EUV Fresnel zoneplate mask-imaging microscope for lithography generations reaching 8 nm

    E-Print Network [OSTI]

    Goldberg, Kenneth A.

    2014-01-01T23:59:59.000Z

    Commissioning a new EUV Fresnel zoneplate mask-imagingimaging system relies on Fresnel zoneplate lenses, which

  1. Commissioning an EUV mask microscope for lithography generations reaching 8 nm

    E-Print Network [OSTI]

    Goldberg, Kenneth A.

    2014-01-01T23:59:59.000Z

    Commissioning an EUV mask microscope for lithographycurrent status of the tool commissioning and the performance1. INTRODUCTION We are now commissioning a new, synchrotron—

  2. Method for characterizing mask defects using image reconstruction from X-ray diffraction patterns

    DOE Patents [OSTI]

    Hau-Riege, Stefan Peter (Fremont, CA)

    2007-05-01T23:59:59.000Z

    The invention applies techniques for image reconstruction from X-ray diffraction patterns on the three-dimensional imaging of defects in EUVL multilayer films. The reconstructed image gives information about the out-of-plane position and the diffraction strength of the defect. The positional information can be used to select the correct defect repair technique. This invention enables the fabrication of defect-free (since repaired) X-ray Mo--Si multilayer mirrors. Repairing Mo--Si multilayer-film defects on mask blanks is a key for the commercial success of EUVL. It is known that particles are added to the Mo--Si multilayer film during the fabrication process. There is a large effort to reduce this contamination, but results are not sufficient, and defects continue to be a major mask yield limiter. All suggested repair strategies need to know the out-of-plane position of the defects in the multilayer.

  3. Context-based automated defect classification system using multiple morphological masks

    DOE Patents [OSTI]

    Gleason, Shaun S. (Knoxville, TN); Hunt, Martin A. (Knoxville, TN); Sari-Sarraf, Hamed (Lubbock, TX)

    2002-01-01T23:59:59.000Z

    Automatic detection of defects during the fabrication of semiconductor wafers is largely automated, but the classification of those defects is still performed manually by technicians. This invention includes novel digital image analysis techniques that generate unique feature vector descriptions of semiconductor defects as well as classifiers that use these descriptions to automatically categorize the defects into one of a set of pre-defined classes. Feature extraction techniques based on multiple-focus images, multiple-defect mask images, and segmented semiconductor wafer images are used to create unique feature-based descriptions of the semiconductor defects. These feature-based defect descriptions are subsequently classified by a defect classifier into categories that depend on defect characteristics and defect contextual information, that is, the semiconductor process layer(s) with which the defect comes in contact. At the heart of the system is a knowledge database that stores and distributes historical semiconductor wafer and defect data to guide the feature extraction and classification processes. In summary, this invention takes as its input a set of images containing semiconductor defect information, and generates as its output a classification for the defect that describes not only the defect itself, but also the location of that defect with respect to the semiconductor process layers.

  4. Repair of localized defects in multilayer-coated reticle blanks for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Stearns, Daniel G. (Los Altos, CA); Sweeney, Donald W. (San Ramon, CA); Mirkarimi, Paul B. (Sunol, CA)

    2004-11-23T23:59:59.000Z

    A method is provided for repairing defects in a multilayer coating layered onto a reticle blank used in an extreme ultraviolet lithography (EUVL) system. Using high lateral spatial resolution, energy is deposited in the multilayer coating in the vicinity of the defect. This can be accomplished using a focused electron beam, focused ion beam or a focused electromagnetic radiation. The absorbed energy will cause a structural modification of the film, producing a localized change in the film thickness. The change in film thickness can be controlled with sub-nanometer accuracy by adjusting the energy dose. The lateral spatial resolution of the thickness modification is controlled by the localization of the energy deposition. The film thickness is adjusted locally to correct the perturbation of the reflected field. For example, when the structural modification is a localized film contraction, the repair of a defect consists of flattening a mound or spreading out the sides of a depression.

  5. VUV lithography

    DOE Patents [OSTI]

    George, Edward V. (Livermore, CA); Oster, Yale (Danville, CA); Mundinger, David C. (Stockton, CA)

    1990-01-01T23:59:59.000Z

    Deep UV projection lithography can be performed using an e-beam pumped solid excimer UV source, a mask, and a UV reduction camera. The UV source produces deep UV radiation in the range 1700-1300A using xenon, krypton or argon; shorter wavelengths of 850-650A can be obtained using neon or helium. A thin solid layer of the gas is formed on a cryogenically cooled plate and bombarded with an e-beam to cause fluorescence. The UV reduction camera utilizes multilayer mirrors having high reflectivity at the UV wavelength and images the mask onto a resist coated substrate at a preselected demagnification. The mask can be formed integrally with the source as an emitting mask.

  6. Comparison of fast 3D simulation and actinic inspection for EUV masks with buries defects

    SciTech Connect (OSTI)

    Clifford, C. H.; Wiraatmadja, S.; Chan, T. T.; Neureuther, A. R.; Goldberg, K. A.; Mochi, I.; Liang, T.

    2009-02-23T23:59:59.000Z

    Aerial images for isolated defects and the interactions of defects with features are compared between the Actinic Inspection Tool (AIT) at Lawrence Berkeley National Laboratory (LBNL) and the fast EUV simulation program RADICAL. Comparisons between AIT images from August 2007 and RADICAL simulations are used to extract aberrations. At this time astigmatism was the dominant aberration with a value of 0.55 waves RMS. Significant improvements in the imaging performance of the AIT were made between August 2007 and December 2008. A good match will be shown between the most recent AIT images and RADICAL simulations without aberrations. These comparisons will demonstrate that a large defect, in this case 7nm tall on the surface, is still printable even if it is centered under the absorber line. These comparisons also suggest that the minimum defect size is between 1.5nm and 0.8nm surface height because a 1.5nm defect was printable but a 0.8nm was not. Finally, the image of a buried defect near an absorber line through focus will demonstrate an inversion in the effect of the defect from a protrusion of the dark line into the space to a protrusion of the space into the line.

  7. Diffractive optics for maskless lithography and imaging

    E-Print Network [OSTI]

    Menon, Rajesh, 1976-

    2003-01-01T23:59:59.000Z

    Semiconductor industry has primarily been driven by the capability of lithography to pattern smaller and smaller features. However due to increasing mask costs and complexity, and increasing tool costs, the state-of-the-art ...

  8. Method for fabricating an ultra-low expansion mask blank having a crystalline silicon layer

    DOE Patents [OSTI]

    Cardinale, Gregory F. (Oakland, CA)

    2002-01-01T23:59:59.000Z

    A method for fabricating masks for extreme ultraviolet lithography (EUVL) using Ultra-Low Expansion (ULE) substrates and crystalline silicon. ULE substrates are required for the necessary thermal management in EUVL mask blanks, and defect detection and classification have been obtained using crystalline silicon substrate materials. Thus, this method provides the advantages for both the ULE substrate and the crystalline silicon in an Extreme Ultra-Violet (EUV) mask blank. The method is carried out by bonding a crystalline silicon wafer or member to a ULE wafer or substrate and thinning the silicon to produce a 5-10 .mu.m thick crystalline silicon layer on the surface of the ULE substrate. The thinning of the crystalline silicon may be carried out, for example, by chemical mechanical polishing and if necessary or desired, oxidizing the silicon followed by etching to the desired thickness of the silicon.

  9. An Ice Lithography Instrument Anpan Han 1, John Chervinsky2

    E-Print Network [OSTI]

    Page 1 An Ice Lithography Instrument Anpan Han 1, John Chervinsky2 , Daniel Branton3 , and J. A a new nano-patterning method called ice lithography, where ice is used as the resist. Water vapor. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice

  10. Mask fabrication process

    DOE Patents [OSTI]

    Cardinale, Gregory F. (Oakland, CA)

    2000-01-01T23:59:59.000Z

    A method for fabricating masks and reticles useful for projection lithography systems. An absorber layer is conventionally patterned using a pattern and etch process. Following the step of patterning, the entire surface of the remaining top patterning photoresist layer as well as that portion of an underlying protective photoresist layer where absorber material has been etched away is exposed to UV radiation. The UV-exposed regions of the protective photoresist layer and the top patterning photoresist layer are then removed by solution development, thereby eliminating the need for an oxygen plasma etch and strip and chances for damaging the surface of the substrate or coatings.

  11. Virtual mask digital electron beam lithography

    DOE Patents [OSTI]

    Baylor, Larry R. (Farragut, TN); Thomas, Clarence E. (Knoxville, TN); Voelkl, Edgar (Oak Ridge, TN); Moore, James A. (Powell, TN); Simpson, Michael L. (Knoxville, TN); Paulus, Michael J. (Knoxville, TN)

    1999-01-01T23:59:59.000Z

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made.

  12. Extreme ultraviolet lithography machine

    DOE Patents [OSTI]

    Tichenor, Daniel A. (Castro Valley, CA); Kubiak, Glenn D. (Livermore, CA); Haney, Steven J. (Tracy, CA); Sweeney, Donald W. (San Ramon, CA)

    2000-01-01T23:59:59.000Z

    An extreme ultraviolet lithography (EUVL) machine or system for producing integrated circuit (IC) components, such as transistors, formed on a substrate. The EUVL machine utilizes a laser plasma point source directed via an optical arrangement onto a mask or reticle which is reflected by a multiple mirror system onto the substrate or target. The EUVL machine operates in the 10-14 nm wavelength soft x-ray photon. Basically the EUV machine includes an evacuated source chamber, an evacuated main or project chamber interconnected by a transport tube arrangement, wherein a laser beam is directed into a plasma generator which produces an illumination beam which is directed by optics from the source chamber through the connecting tube, into the projection chamber, and onto the reticle or mask, from which a patterned beam is reflected by optics in a projection optics (PO) box mounted in the main or projection chamber onto the substrate. In one embodiment of a EUVL machine, nine optical components are utilized, with four of the optical components located in the PO box. The main or projection chamber includes vibration isolators for the PO box and a vibration isolator mounting for the substrate, with the main or projection chamber being mounted on a support structure and being isolated.

  13. Method for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (Livermore, CA); Kubiak, Glenn D. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  14. Method for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (727 Clara St., Livermore, Alameda County, CA 94550); Kubiak, G. D. (475 Maple St., Livermore, Alameda County, CA 94550)

    2000-01-01T23:59:59.000Z

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  15. Maskless lithography

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Stulen, Richard H. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    The present invention provides a method for maskless lithography. A plurality of individually addressable and rotatable micromirrors together comprise a two-dimensional array of micromirrors. Each micromirror in the two-dimensional array can be envisioned as an individually addressable element in the picture that comprises the circuit pattern desired. As each micromirror is addressed it rotates so as to reflect light from a light source onto a portion of the photoresist coated wafer thereby forming a pixel within the circuit pattern. By electronically addressing a two-dimensional array of these micromirrors in the proper sequence a circuit pattern that is comprised of these individual pixels can be constructed on a microchip. The reflecting surface of the micromirror is configured in such a way as to overcome coherence and diffraction effects in order to produce circuit elements having straight sides.

  16. Validity of the thin mask approximation in extreme ultraviolet mask roughness simulations

    SciTech Connect (OSTI)

    Naulleau, Patrick; George, Simi

    2011-01-26T23:59:59.000Z

    In the case of extreme ultraviolet (EUV) lithography, modeling has shown that reflector phase roughness on the lithographic mask is a significant concern due to the image plan speckle it causes and the resulting line-edge roughness on imaged features. Modeling results have recently been used to determine the requirements for future production worthy masks yielding the extremely stringent specification of 50 pm rms roughness. Owing to the scale of the problem in terms of memory requirements, past modeling results have all been based on the thin mask approximation. EUV masks, however, are inherently three dimensional in nature and thus the question arises as to the validity of the thin mask approximation. Here we directly compare image plane speckle calculation results using the fast two dimensional thin mask model to rigorous finite-difference time-domain results and find the two methods to be comparable.

  17. Coatings on reflective mask substrates

    DOE Patents [OSTI]

    Tong, William Man-Wai (Oakland, CA); Taylor, John S. (Livermore, CA); Hector, Scott D. (Oakland, CA); Mangat, Pawitter J. S. (Gilbert, AZ); Stivers, Alan R. (San Jose, CA); Kofron, Patrick G. (San Jose, CA); Thompson, Matthew A. (Austin, TX)

    2002-01-01T23:59:59.000Z

    A process for creating a mask substrate involving depositing: 1) a coating on one or both sides of a low thermal expansion material EUVL mask substrate to improve defect inspection, surface finishing, and defect levels; and 2) a high dielectric coating, on the backside to facilitate electrostatic chucking and to correct for any bowing caused by the stress imbalance imparted by either other deposited coatings or the multilayer coating of the mask substrate. An film, such as TaSi, may be deposited on the front side and/or back of the low thermal expansion material before the material coating to balance the stress. The low thermal expansion material with a silicon overlayer and a silicon and/or other conductive underlayer enables improved defect inspection and stress balancing.

  18. Absorbance modulation optical lithography

    E-Print Network [OSTI]

    Tsai, Hsin-Yu Sidney

    2007-01-01T23:59:59.000Z

    In this thesis, the concept of absorbance-modulation optical lithography (AMOL) is described, and the feasibility experimentally verified. AMOL is an implementation of nodal lithography, which is not bounded by the diffraction ...

  19. Maskless, resistless ion beam lithography

    SciTech Connect (OSTI)

    Ji, Qing

    2003-03-10T23:59:59.000Z

    As the dimensions of semiconductor devices are scaled down, in order to achieve higher levels of integration, optical lithography will no longer be sufficient for the needs of the semiconductor industry. Alternative next-generation lithography (NGL) approaches, such as extreme ultra-violet (EUV), X-ray, electron-beam, and ion projection lithography face some challenging issues with complicated mask technology and low throughput. Among the four major alternative NGL approaches, ion beam lithography is the only one that can provide both maskless and resistless patterning. As such, it can potentially make nano-fabrication much simpler. This thesis investigates a focused ion beam system for maskless, resistless patterning that can be made practical for high-volume production. In order to achieve maskless, resistless patterning, the ion source must be able to produce a variety of ion species. The compact FIB system being developed uses a multicusp plasma ion source, which can generate ion beams of various elements, such as O{sub 2}{sup +}, BF{sub 2}{sup +}, P{sup +} etc., for surface modification and doping applications. With optimized source condition, around 85% of BF{sub 2}{sup +}, over 90% of O{sub 2}{sup +} and P{sup +} have been achieved. The brightness of the multicusp-plasma ion source is a key issue for its application to maskless ion beam lithography. It can be substantially improved by optimizing the source configuration and extractor geometry. Measured brightness of 2 keV He{sup +} beam is as high as 440 A/cm{sup 2} {center_dot} Sr, which represents a 30x improvement over prior work. Direct patterning of Si thin film using a focused O{sub 2}{sup +} ion beam has been investigated. A thin surface oxide film can be selectively formed using 3 keV O{sub 2}{sup +} ions with the dose of 10{sup 15} cm{sup -2}. The oxide can then serve as a hard mask for patterning of the Si film. The process flow and the experimental results for directly patterned poly-Si features are presented. The formation of shallow pn-junctions in bulk silicon wafers by scanning focused P{sup +} beam implantation at 5 keV is also presented. With implantation dose of around 10{sup 16} cm{sup -2}, the electron concentration is about 2.5 x 10{sup 18} cm{sup -3} and electron mobility is around 200 cm{sup 2}/V{center_dot}s. To demonstrate the suitability of scanning FIB lithography for the manufacture of integrated circuit devices, SOI MOSFET fabrication using the maskless, resistless ion beam lithography is demonstrated. An array of microcolumns can be built by stacking multi-aperture electrode and insulator layers. Because the multicusp plasma source can achieve uniform ion density over a large area, it can be used in conjunction with the array of microcolumns, for massively parallel FIB processing to achieve reasonable exposure throughput.

  20. Photoresist composition for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (Alameda County, CA); Kubiak, G. D. (Alameda County, CA)

    1999-01-01T23:59:59.000Z

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods. A photoresist composition for extreme ultraviolet radiation of boron carbide polymers, hydrochlorocarbons and mixtures thereof.

  1. Chains of quantum dot molecules grown on Si surface pre-patterned by ion-assisted nanoimprint lithography

    SciTech Connect (OSTI)

    Smagina, Zh. V.; Stepina, N. P., E-mail: stepina@isp.nsc.ru; Zinovyev, V. A.; Kuchinskaya, P. A. [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Lavrenteva 13, 630090 Novosibirsk (Russian Federation); Novikov, P. L.; Dvurechenskii, A. V. [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Lavrenteva 13, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova, 2, 630090 Novosibirsk (Russian Federation)

    2014-10-13T23:59:59.000Z

    An original approach based on the combination of nanoimprint lithography and ion irradiation through mask has been developed for fabrication of large-area periodical pattern on Si(100). Using the selective etching of regions amorphized by ion irradiation ordered structures with grooves and ridges were obtained. The shape and depth of the relief were governed by ion energy and by the number of etching stages as well. Laterally ordered chains of Ge quantum dots were fabricated by molecular beam epitaxy of Ge on the pre-patterned Si substrates. For small amount of Ge deposited chains contain separate quantum dot molecules. The increase of deposition amount leads to overlapping of quantum dot molecules with formation of dense homogeneous chains of quantum dots. It was shown that the residual irradiation-induced bulk defects underneath the grooves suppress nucleation of Ge islands at the bottom of grooves. On pre-patterned substrates with whole defect regions, etched quantum dots grow at the bottom of grooves. The observed location of Ge quantum dots is interpreted in terms of local strain-mediated surface chemical potential which controls the sites of islands nucleation. The local chemical potential is affected by additional strain formed by the residual defects. It was shown by molecular dynamics calculations that these defects form the compressive strain at the bottom of grooves.

  2. Automation of soft lithography

    E-Print Network [OSTI]

    Kim, Hyung-Jun

    2006-01-01T23:59:59.000Z

    This dissertation is a final documentation of the project whose goal is demonstrating manufacturability of soft lithography. Specifically, our target is creating micron scale patterns of resists on a 3 square inch, relatively ...

  3. Contact thermal lithography

    E-Print Network [OSTI]

    Schmidt, Aaron Jerome, 1979-

    2004-01-01T23:59:59.000Z

    Contact thermal lithography is a method for fabricating microscale patterns using heat transfer. In contrast to photolithography, where the minimum achievable feature size is proportional to the wavelength of light used ...

  4. M&A For Lithography Of Sparse Arrays Of Sub-Micrometer Features

    DOE Patents [OSTI]

    Brueck, Steven R.J. (Albuquerque, NM); Chen, Xiaolan (Albuquerque, NM); Zaidi, Saleem (Albuquerque, NM); Devine, Daniel J. (Los Gatos, CA)

    1998-06-02T23:59:59.000Z

    Methods and apparatuses are disclosed for the exposure of sparse hole and/or mesa arrays with line:space ratios of 1:3 or greater and sub-micrometer hole and/or mesa diameters in a layer of photosensitive material atop a layered material. Methods disclosed include: double exposure interferometric lithography pairs in which only those areas near the overlapping maxima of each single-period exposure pair receive a clearing exposure dose; double interferometric lithography exposure pairs with additional processing steps to transfer the array from a first single-period interferometric lithography exposure pair into an intermediate mask layer and a second single-period interferometric lithography exposure to further select a subset of the first array of holes; a double exposure of a single period interferometric lithography exposure pair to define a dense array of sub-micrometer holes and an optical lithography exposure in which only those holes near maxima of both exposures receive a clearing exposure dose; combination of a single-period interferometric exposure pair, processing to transfer resulting dense array of sub-micrometer holes into an intermediate etch mask, and an optical lithography exposure to select a subset of initial array to form a sparse array; combination of an optical exposure, transfer of exposure pattern into an intermediate mask layer, and a single-period interferometric lithography exposure pair; three-beam interferometric exposure pairs to form sparse arrays of sub-micrometer holes; five- and four-beam interferometric exposures to form a sparse array of sub-micrometer holes in a single exposure. Apparatuses disclosed include arrangements for the three-beam, five-beam and four-beam interferometric exposures.

  5. Ion beam lithography system

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2005-08-02T23:59:59.000Z

    A maskless plasma-formed ion beam lithography tool provides for patterning of sub-50 nm features on large area flat or curved substrate surfaces. The system is very compact and does not require an accelerator column and electrostatic beam scanning components. The patterns are formed by switching beamlets on or off from a two electrode blanking system with the substrate being scanned mechanically in one dimension. This arrangement can provide a maskless nano-beam lithography tool for economic and high throughput processing.

  6. Electron caustic lithography

    SciTech Connect (OSTI)

    Kennedy, S. M.; Zheng, C. X.; Tang, W. X.; Paganin, D. M.; Jesson, D. E. [School of Physics, Monash University, Victoria, 3800 (Australia); Fu, J. [Department of Mechanical and Aerospace Engineering, Monash University, Victoria, 3800 (Australia)

    2012-06-15T23:59:59.000Z

    A maskless method of electron beam lithography is described which uses the reflection of an electron beam from an electrostatic mirror to produce caustics in the demagnified image projected onto a resist-coated wafer. By varying the electron optics, e.g. via objective lens defocus, both the morphology and dimensions of the caustic features may be controlled, producing a range of bright and tightly focused projected features. The method is illustrated for line and fold caustics and is complementary to other methods of reflective electron beam lithography.

  7. Method and apparatus for inspecting an EUV mask blank

    DOE Patents [OSTI]

    Goldberg, Kenneth A.

    2005-11-08T23:59:59.000Z

    An apparatus and method for at-wavelength EUV mask-blank characterization for inspection of moderate and low spatial frequency coating uniformity using a synchrotron or other source of EUV light. The apparatus provides for rapid, non-destruction, non-contact, at-wavelength qualification of large mask areas, and can be self-calibrating or be calibrated to well-characterized reference samples. It can further check for spatial variation of mask reflectivity or for global differences among masks. The apparatus and method is particularly suited for inspection of coating uniformity and quality and can detect defects in the order of 50 .mu.m and above.

  8. XUV free-electron laser-based projection lithography systems

    SciTech Connect (OSTI)

    Newnam, B.E.

    1990-01-01T23:59:59.000Z

    Free-electron laser sources, driven by rf-linear accelerators, have the potential to operate in the extreme ultraviolet (XUV) spectral range with more than sufficient average power for high-volume projection lithography. For XUV wavelengths from 100 nm to 4 nm, such sources will enable the resolution limit of optical projection lithography to be extended from 0.25 {mu}m to 0.05{mu}m and with an adequate total depth of focus (1 to 2 {mu}m). Recent developments of a photoinjector of very bright electron beams, high-precision magnetic undulators, and ring-resonator cavities raise our confidence that FEL operation below 100 nm is ready for prototype demonstration. We address the motivation for an XUV FEL source for commercial microcircuit production and its integration into a lithographic system, include reflecting reduction masks, reflecting XUV projection optics and alignment systems, and surface-imaging photoresists. 52 refs., 7 figs.

  9. Development of free-electron lasers for xuv projection lithography

    SciTech Connect (OSTI)

    Newnam, B.E.

    1990-01-01T23:59:59.000Z

    Future rf-linac-driven FELs, operating in the range from 4 nm to 100 nm, could be excellent exposure tools for extending the resolution limit of projection optical lithography to {le}0.1 {mu}m and with adequate total depth of focus (1 to 2 {mu}m). When operated at a moderate duty rate of {ge}1%, XUV FELs should be able to supply sufficient average power to support high-volume chip production. Recent developments of the electron beam, magnetic undulator, and resonator mirrors are described which raise our expectation that FEL operation below 100 nm is almost ready for demonstration. Included as a supplement is a review of initial design studies of the reflecting XUV projection optics, fabrication of reflection masks, characterization of photoresists, and the first experimental demonstrations of the capability of projection lithography with 14-nm radiation to produce lines and spaces as small as 0.05 {mu}m. 88 refs., 10 figs.

  10. Soft x-ray reduction camera for submicron lithography

    DOE Patents [OSTI]

    Hawryluk, Andrew M. (2708 Rembrandt Pl., Modesto, CA 95356); Seppala, Lynn G. (7911 Mines Rd., Livermore, CA 94550)

    1991-01-01T23:59:59.000Z

    Soft x-ray projection lithography can be performed using x-ray optical components and spherical imaging lenses (mirrors), which form an x-ray reduction camera. The x-ray reduction is capable of projecting a 5x demagnified image of a mask onto a resist coated wafer using 4.5 nm radiation. The diffraction limited resolution of this design is about 135 nm with a depth of field of about 2.8 microns and a field of view of 0.2 cm.sup.2. X-ray reflecting masks (patterned x-ray multilayer mirrors) which are fabricated on thick substrates and can be made relatively distortion free are used, with a laser produced plasma for the source. Higher resolution and/or larger areas are possible by varying the optic figures of the components and source characteristics.

  11. Soft x-ray reduction camera for submicron lithography

    DOE Patents [OSTI]

    Hawryluk, A.M.; Seppala, L.G.

    1991-03-26T23:59:59.000Z

    Soft x-ray projection lithography can be performed using x-ray optical components and spherical imaging lenses (mirrors), which form an x-ray reduction camera. The x-ray reduction is capable of projecting a 5x demagnified image of a mask onto a resist coated wafer using 4.5 nm radiation. The diffraction limited resolution of this design is about 135 nm with a depth of field of about 2.8 microns and a field of view of 0.2 cm[sup 2]. X-ray reflecting masks (patterned x-ray multilayer mirrors) which are fabricated on thick substrates and can be made relatively distortion free are used, with a laser produced plasma for the source. Higher resolution and/or larger areas are possible by varying the optic figures of the components and source characteristics. 9 figures.

  12. Programmable imprint lithography template

    DOE Patents [OSTI]

    Cardinale, Gregory F. (Oakland, CA); Talin, Albert A. (Livermore, CA)

    2006-10-31T23:59:59.000Z

    A template for imprint lithography (IL) that reduces significantly template production costs by allowing the same template to be re-used for several technology generations. The template is composed of an array of spaced-apart moveable and individually addressable rods or plungers. Thus, the template can be configured to provide a desired pattern by programming the array of plungers such that certain of the plungers are in an "up" or actuated configuration. This arrangement of "up" and "down" plungers forms a pattern composed of protruding and recessed features which can then be impressed onto a polymer film coated substrate by applying a pressure to the template impressing the programmed configuration into the polymer film. The pattern impressed into the polymer film will be reproduced on the substrate by subsequent processing.

  13. Critical illumination condenser for x-ray lithography

    DOE Patents [OSTI]

    Cohen, S.J.; Seppala, L.G.

    1998-04-07T23:59:59.000Z

    A critical illumination condenser system is disclosed, particularly adapted for use in extreme ultraviolet (EUV) projection lithography based on a ring field imaging system and a laser produced plasma source. The system uses three spherical mirrors and is capable of illuminating the extent of the mask plane by scanning either the primary mirror or the laser plasma source. The angles of radiation incident upon each mirror of the critical illumination condenser vary by less than eight (8) degrees. For example, the imaging system in which the critical illumination condenser is utilized has a 200 {micro}m source and requires a magnification of 26. The three spherical mirror system constitutes a two mirror inverse Cassegrain, or Schwarzschild configuration, with a 25% area obstruction (50% linear obstruction). The third mirror provides the final pupil and image relay. The mirrors include a multilayer reflective coating which is reflective over a narrow bandwidth. 6 figs.

  14. Actinic characterization of EUV bump-type phase defects

    SciTech Connect (OSTI)

    Goldberg, Kenneth A.; Mochi, Iacopo; Liang, Ted

    2011-01-10T23:59:59.000Z

    Despite tremendous progress and learning with EUV lithography, quantitative experimental information about the severity of point-like phase defects remains in short supply. We present a study of measured, EUV aerial images from a series of well-characterized, open-field, bump-type programmed phase defects, created on a substrate before multilayer deposition.

  15. IIII--E. Scanning Probe LithographyE. Scanning Probe Lithography Voltage pulse

    E-Print Network [OSTI]

    Liu, Kai

    Molnar, PRB 57 14028 (1998) Lithography Liu, UCD Phy250-1, 2011, NanoFab34 Contamination PRB 57 14028 GrowthStep Growth--66 Annealed NaCl substrates Sugawara & Scheinfein, PRB 56, 8499 (1997). Lithography

  16. X-ray lithography source

    DOE Patents [OSTI]

    Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

    1991-01-01T23:59:59.000Z

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  17. X-ray lithography source

    DOE Patents [OSTI]

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.

    1991-12-31T23:59:59.000Z

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

  18. Fabrication of high-T sub c Josephson effect devices by natural lithography

    SciTech Connect (OSTI)

    Dozier, W.D.; Daly, K.P.; Hu, R.; Platt, C.E.; Wire, M.S. (TRW Space and Technology Group, Redondo Beach, CA (United States))

    1991-03-01T23:59:59.000Z

    This paper reports on deposited thin films of YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) on LaAlO{sub 3} substrates previously textured with submicron which features by the use of natural lithography (the use of monolayers of polystyrene microspheres as lithographic masks). This weakens the superconducting properties due to reduced connectivity in the film. Devices fabricated using localized textured regions have shown Josephson coupling. Weak links have shown Shapiro steps at the expected voltage intervals. Magnetic field induced modulation in the detected RF voltage with the geometrically correct periodicity has been observed in RF SQUIDs over a limited temperature range.

  19. Sub-10-nm lithography with light-ion beams

    E-Print Network [OSTI]

    Winston, Donald, Ph. D. Massachusetts Institute of Technology

    2012-01-01T23:59:59.000Z

    Scanning-electron-beam lithography (SEBL) is the workhorse of nanoscale lithography in part because of the high brightness of the Schottky source of electrons, but also benefiting from decades of incremental innovation and ...

  20. Scanning-helium-ion-beam lithography with hydrogen silsesquioxane resist

    E-Print Network [OSTI]

    Winston, Donald

    A scanning-helium-ion-beam microscope is now commercially available. This microscope can be used to perform lithography similar to, but of potentially higher resolution than, scanning electron-beam lithography. This article ...

  1. II. Types of LithographyII. Types of Lithography A. Photolithography (optical, UV, EUV) F. Step Growth

    E-Print Network [OSTI]

    Liu, Kai

    lithography S i b I. Self-Assembly J NanotemplatesE. Scanning Probe Voltage pulse CVD Local electrodeposition J. Nanotemplates Diblock copolymer Sphere Alumina membraneLocal electrodeposition Dip Interference Lithography FIG. 1. SEM images of nickel dot arrays fabricated by x-ray interference lithography

  2. Magnetic nanostructures patterned by block copolymer lithography

    E-Print Network [OSTI]

    Ilievski, Filip, 1980-

    2008-01-01T23:59:59.000Z

    The aim of this research was twofold: understanding the methods of patterning magnetic films using self-assembled block copolymer masks and examining the magnetic reversal mechanisms of as deposited and patterned magnetic ...

  3. EUV lithography cost of ownership analysis

    SciTech Connect (OSTI)

    Hawryluk, A.M.; Ceglio, N.M.

    1995-01-19T23:59:59.000Z

    The cost of fabricating state-of-the-art integrated circuits (ICs) has been increasing and it will likely be economic rather than technical factors that ultimately limit the progress of ICs toward smaller devices. It is estimated that lithography currently accounts for approximately one-third the total cost of fabricating modem ICs({sup 1}). It is expected that this factor will be fairly stable for the forseeable future, and as a result, any lithographic process must be cost-effective before it can be considered for production. Additionally, the capital equipment cost for a new fabrication facility is growing at an exponential rate (2); it will soon require a multibillion dollar investment in capital equipment alone to build a manufacturing facility. In this regard, it is vital that any advanced lithography candidate justify itself on the basis of cost effectiveness. EUV lithography is no exception and close attention to issues of wafer fabrication costs have been a hallmark of its early history. To date, two prior cost analyses have been conducted for EUV lithography (formerly called {open_quotes}Soft X-ray Projection Lithography{close_quotes}). The analysis by Ceglio, et. al., provided a preliminary system design, set performance specifications and identified critical technical issues for cost control. A follow-on analysis by Early, et.al., studied the impact of issues such as step time, stepper overhead, tool utilization, escalating photoresist costs and limited reticle usage on wafer exposure costs. This current study provides updated system designs and specifications and their impact on wafer exposure costs. In addition, it takes a first cut at a preliminary schematic of an EUVL fabrication facility along with an estimate of the capital equipment costs for such a facility.

  4. Carbon contamination topography analysis of EUV masks

    E-Print Network [OSTI]

    Fan, Y.-J.

    2010-01-01T23:59:59.000Z

    induced carbon contamination of extreme ultraviolet optics,"and A. Izumi. "Carbon contamination of EL'V mask: filmEffect of Carbon Contamination on the Printing Performance

  5. Nanofabrication on unconventional substrates using transferred hard masks

    E-Print Network [OSTI]

    Li, Luozhou

    A major challenge in nanofabrication is to pattern unconventional substrates that cannot be processed for a variety of reasons, such as incompatibility with spin coating, electron beam lithography, optical lithography, or ...

  6. Multilevel interference lithography--fabricating sub-wavelength periodic nanostructures

    E-Print Network [OSTI]

    Chang, Chih-Hao, 1980-

    2008-01-01T23:59:59.000Z

    Periodic nanostructures have many exciting applications, including high-energy spectroscopy, patterned magnetic media, photonic crystals, and templates for self-assembly. Interference lithography (IL) is an attractive ...

  7. Resolution Improvement and Pattern Generator Development for theMaskless Micro-Ion-Beam Reduction Lithography System

    SciTech Connect (OSTI)

    Jiang, Ximan

    2006-05-18T23:59:59.000Z

    The shrinking of IC devices has followed the Moore's Law for over three decades, which states that the density of transistors on integrated circuits will double about every two years. This great achievement is obtained via continuous advance in lithography technology. With the adoption of complicated resolution enhancement technologies, such as the phase shifting mask (PSM), the optical proximity correction (OPC), optical lithography with wavelength of 193 nm has enabled 45 nm printing by immersion method. However, this achievement comes together with the skyrocketing cost of masks, which makes the production of low volume application-specific IC (ASIC) impractical. In order to provide an economical lithography approach for low to medium volume advanced IC fabrication, a maskless ion beam lithography method, called Maskless Micro-ion-beam Reduction Lithography (MMRL), has been developed in the Lawrence Berkeley National Laboratory. The development of the prototype MMRL system has been described by Dr. Vinh Van Ngo in his Ph.D. thesis. But the resolution realized on the prototype MMRL system was far from the design expectation. In order to improve the resolution of the MMRL system, the ion optical system has been investigated. By integrating a field-free limiting aperture into the optical column, reducing the electromagnetic interference and cleaning the RF plasma, the resolution has been improved to around 50 nm. Computational analysis indicates that the MMRL system can be operated with an exposure field size of 0.25 mm and a beam half angle of 1.0 mrad on the wafer plane. Ion-ion interactions have been studied with a two-particle physics model. The results are in excellent agreement with those published by the other research groups. The charge-interaction analysis of MMRL shows that the ion-ion interactions must be reduced in order to obtain a throughput higher than 10 wafers per hour on 300-mm wafers. In addition, two different maskless lithography strategies have been studied. The dependence of the throughput with the exposure field size and the speed of the mechanical stage has been investigated. In order to perform maskless lithography, different micro-fabricated pattern generators have been developed for the MMRL system. Ion beamlet switching has been successfully demonstrated on the MMRL system. A positive bias voltage around 10 volts is sufficient to switch off the ion current on the micro-fabricated pattern generators. Some unexpected problems, such as the high-energy secondary electron radiations, have been discovered during the experimental investigation. Thermal and structural analysis indicates that the aperture displacement error induced by thermal expansion can satisfy the 3{delta} CD requirement for lithography nodes down to 25 nm. The cross-talking effect near the surface and inside the apertures of the pattern generator has been simulated in a 3-D ray-tracing code. New pattern generator design has been proposed to reduce the cross-talking effect. In order to eliminate the surface charging effect caused by the secondary electrons, a new beam-switching scheme in which the switching electrodes are immersed in the plasma has been demonstrated on a mechanically fabricated pattern generator.

  8. CMA Operating Manual: Canon Mask Aligner Introduction

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    CMA Operating Manual: Canon Mask Aligner Introduction Use the Canon PLA-501F Mask Aligner (See Fig: Dan Haskell, 1125 Kemper Hall Corey Wolin, 1125 Kemper Hall Lab Manager Pre-operational Checklist Before you enter the cleanroom: 1. Have you arranged training from the superuser or lab manager

  9. Simplified models for mask roughness induced LER

    SciTech Connect (OSTI)

    McClinton, Brittany; Naulleau, Patrick

    2011-02-21T23:59:59.000Z

    The ITRS requires < 1.2nm line-edge roughness (LER) for the 22nm half-pitch node. Currently, we can consistently achieve only about 3nm LER. Further progress requires understanding the principle causes of LER. Much work has already been done on how both the resist and LER on the mask effect the final printed LER. What is poorly understood, however, is the extent to which system-level effects such as mask surface roughness, illumination conditions, and defocus couple to speckle at the image plane, and factor into LER limits. Presently, mask-roughness induced LER is studied via full 2D aerial image modeling and subsequent analysis of the resulting image. This method is time consuming and cumbersome. It is, therefore, the goal of this research to develop a useful 'rule-of-thumb' analytic model for mask roughness induced LER to expedite learning and understanding.

  10. Two-dimensional Photonic Crystals Fabricated by Nanoimprint Lithography

    E-Print Network [OSTI]

    Chen, A.

    We report on the process parameters of nanoimprint lithography (NIL) for the fabrication of two-dimensional (2-D) photonic crystals. The nickel mould with 2-D photonic crystal patterns covering the area up to 20mm˛ is ...

  11. Toward nano-accuracy in scanning beam interference lithography

    E-Print Network [OSTI]

    Montoya, Juan, 1976-

    2006-01-01T23:59:59.000Z

    Scanning beam interference lithography is a technique developed in our laboratory which uses interfering beams and a scanning stage to rapidly pattern gratings over large areas (300x300 mm2) with high precision. The ...

  12. Achieving sub-10-nm resolution using scanning electron beam lithography

    E-Print Network [OSTI]

    Cord, Bryan M. (Bryan Michael), 1980-

    2009-01-01T23:59:59.000Z

    Achieving the highest possible resolution using scanning-electron-beam lithography (SEBL) has become an increasingly urgent problem in recent years, as advances in various nanotechnology applications have driven demand for ...

  13. Masking line foregrounds in intensity mapping surveys

    E-Print Network [OSTI]

    Breysse, Patrick C; Kamionkowski, Marc

    2015-01-01T23:59:59.000Z

    We address the problem of line confusion in intensity mapping surveys and explore the possibility to mitigate line foreground contamination by progressively masking the brightest pixels in the observed map. We consider experiments targeting CO(1-0) at $z=3$, Ly$\\alpha$ at $z=7$, and CII at $z=7$, and use simulated intensity maps, which include both clustering and shot noise components of the signal and possible foregrounds, in order to test the efficiency of our method. We find that for CO and Ly$\\alpha$ it is quite possible to remove most of the foreground contribution from the maps via only 1%-3% pixel masking. The CII maps will be more difficult to clean, however, due to instrumental constraints and the high-intensity foreground contamination involved. While the masking procedure sacrifices much of the astrophysical information present in our maps, we demonstrate that useful cosmological information in the targeted lines can be successfully retrieved.

  14. Protective mask for airborne toxic substances

    SciTech Connect (OSTI)

    Shoemaker, C.J.; Scavnicky, J.A.; Little, M.E.; Hagy, E.M.; Bloom, A.

    1983-10-21T23:59:59.000Z

    A protective mask is described which includes a one-piece face piece molded of a transparent elastomer. A visor in the face piece provides panoramic visibility and is resilient enough to deform under applied force to permit improved use of optical devices. Identical left and right cheek fittings permit installation of a canister on either side so that the same mask can be used by right-handed and left-handed wearers voice for use with a telephone and the like. Air deflectors inside the mask adjacent the left and right cheek fittings deflect de-foging air along the inside surface of the visor when either left or right or both cheek fittings are used for attachment of a canister. A sealing adapter permits sealing around earpiece shafts of eyeglasses.

  15. Free electron laser with masked chicane

    DOE Patents [OSTI]

    Nguyen, Dinh C. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A free electron laser (FEL) is provided with an accelerator for outputting electron beam pulses; a buncher for modulating each one of the electron beam pulses to form each pulse into longitudinally dispersed bunches of electrons; and a wiggler for generating coherent light from the longitudinally dispersed bunches of electrons. The electron beam buncher is a chicane having a mask for physically modulating the electron beam pulses to form a series of electron beam bunches for input to the wiggler. In a preferred embodiment, the mask is located in the chicane at a position where each electron beam pulse has a maximum dispersion.

  16. Carbon contamination topography analysis of EUV masks

    SciTech Connect (OSTI)

    Fan, Y.-J.; Yankulin, L.; Thomas, P.; Mbanaso, C.; Antohe, A.; Garg, R.; Wang, Y.; Murray, T.; Wuest, A.; Goodwin, F.; Huh, S.; Cordes, A.; Naulleau, P.; Goldberg, K. A.; Mochi, I.; Gullikson, E.; Denbeaux, G.

    2010-03-12T23:59:59.000Z

    The impact of carbon contamination on extreme ultraviolet (EUV) masks is significant due to throughput loss and potential effects on imaging performance. Current carbon contamination research primarily focuses on the lifetime of the multilayer surfaces, determined by reflectivity loss and reduced throughput in EUV exposure tools. However, contamination on patterned EUV masks can cause additional effects on absorbing features and the printed images, as well as impacting the efficiency of cleaning process. In this work, several different techniques were used to determine possible contamination topography. Lithographic simulations were also performed and the results compared with the experimental data.

  17. Spatiotemporal discrimination model predicts temporal masking functions

    E-Print Network [OSTI]

    CA 94035 a b Institute for Optical Research, Stockholm, Sweden W ABSTRACT e present a simplified dual, and masking based on local spatio­temporal contrast energy. The contras ensitivity filter parameters for the lack of space­time l s separability in contrast detection, the model has separate sustained

  18. Automated mask creation from a 3D model using Faethm.

    SciTech Connect (OSTI)

    Schiek, Richard Louis; Schmidt, Rodney Cannon

    2007-11-01T23:59:59.000Z

    We have developed and implemented a method which given a three-dimensional object can infer from topology the two-dimensional masks needed to produce that object with surface micro-machining. The masks produced by this design tool can be generic, process independent masks, or if given process constraints, specific for a target process. This design tool calculates the two-dimensional mask set required to produce a given three-dimensional model by investigating the vertical topology of the model.

  19. High resolution imaging and lithography using interference of light and surface plasmon waves

    E-Print Network [OSTI]

    Kim, Yang-Hyo

    2007-01-01T23:59:59.000Z

    The resolution of optical imaging and lithography is limited by the wave nature of light. Studies have been undertaken to overcome the diffraction limit for imaging and lithography. In our lab, the standing wave surface ...

  20. Design and prototype : a manufacturing system for the soft lithography technique

    E-Print Network [OSTI]

    Cao, Arthur Y. (Arthur Yao)

    2006-01-01T23:59:59.000Z

    Ever since 1998 when the term "soft lithography" was first created, soft lithography techniques have drawn close attention of the academia and the industry. Micro contact printing is by far the most widely used soft ...

  1. Pattern-placement-error detection for spatial-phase-locked e-beam lithography (SPLEBL)

    E-Print Network [OSTI]

    Caramana, Cynthia L. (Cynthia Louise), 1978-

    2004-01-01T23:59:59.000Z

    Spatial-phase-locked electron-beam lithography (SPLEBL) is a new paradigm for scanning electron-beam lithography (SEBL) that permits nanometer-level pattern placement accuracy. Unlike conventional SEBL systems which run ...

  2. Mask-to-wafer alignment system

    DOE Patents [OSTI]

    Sweatt, William C.; Tichenor, Daniel A.; Haney, Steven J.

    2003-11-04T23:59:59.000Z

    A modified beam splitter that has a hole pattern that is symmetric in one axis and anti-symmetric in the other can be employed in a mask-to-wafer alignment device. The device is particularly suited for rough alignment using visible light. The modified beam splitter transmits and reflects light from a source of electromagnetic radiation and it includes a substrate that has a first surface facing the source of electromagnetic radiation and second surface that is reflective of said electromagnetic radiation. The substrate defines a hole pattern about a central line of the substrate. In operation, an input beam from a camera is directed toward the modified beam splitter and the light from the camera that passes through the holes illuminates the reticle on the wafer. The light beam from the camera also projects an image of a corresponding reticle pattern that is formed on the mask surface of the that is positioned downstream from the camera. Alignment can be accomplished by detecting the radiation that is reflected from the second surface of the modified beam splitter since the reflected radiation contains both the image of the pattern from the mask and a corresponding pattern on the wafer.

  3. Removable pellicle for lithographic mask protection and handling

    DOE Patents [OSTI]

    Klebanoff, Leonard E. (Dublin, CA); Rader, Daniel J. (Albuquerque, NM); Hector, Scott D. (Oakland, CA); Nguyen, Khanh B. (Sunnyvale, CA); Stulen, Richard H. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    A removable pellicle for a lithographic mask that provides active and robust particle protection, and which utilizes a traditional pellicle and two deployments of thermophoretic protection to keep particles off the mask. The removable pellicle is removably attached via a retaining structure to the mask substrate by magnetic attraction with either contacting or non-contacting magnetic capture mechanisms. The pellicle retaining structural is composed of an anchor piece secured to the mask substrate and a frame member containing a pellicle. The anchor piece and the frame member are in removable contact or non-contact by the magnetic capture or latching mechanism. In one embodiment, the frame member is retained in a floating (non-contact) relation to the anchor piece by magnetic levitation. The frame member and the anchor piece are provided with thermophoretic fins which are interdigitated to prevent particles from reaching the patterned area of the mask. Also, the anchor piece and mask are maintained at a higher temperature than the frame member and pellicle which also prevents particles from reaching the patterned mask area by thermophoresis. The pellicle can be positioned over the mask to provide particle protection during mask handling, inspection, and pumpdown, but which can be removed manually or robotically for lithographic use of the mask.

  4. Condenser for extreme-UV lithography with discharge source

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Kubiak, Glenn D. (Livermore, CA)

    2001-01-01T23:59:59.000Z

    Condenser system, for use with a ringfield camera in projection lithography, employs quasi grazing-incidence collector mirrors that are coated with a suitable reflective metal such as ruthenium to collect radiation from a discharge source to minimize the effect of contaminant accumulation on the collecting mirrors.

  5. Ultratech Develops an Improved Lithography Tool for LED Wafer Manufacturing

    Broader source: Energy.gov [DOE]

    Ultratech modified an existing lithography tool used for semiconductor manufacturing to better meet the cost and performance targets of the high-brightness LED manufacturing industry. The goal was to make the equipment compatible with the wide range of substrate diameters and thicknesses prevalent in the industry while reducing the capital cost and the overall cost of ownership (COO).

  6. Diffractive element in extreme-UV lithography condenser

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Ray-Chaudhurl, Avijit K. (Livermore, CA)

    2000-01-01T23:59:59.000Z

    Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

  7. Digital microfluidics using soft lithography{ John Paul Urbanski,a

    E-Print Network [OSTI]

    Amarasinghe, Saman

    Digital microfluidics using soft lithography{ John Paul Urbanski,a William Thies,b Christopher published as an Advance Article on the web 29th November 2005 DOI: 10.1039/b510127a Although microfluidic software to drive the pumps, valves, and electrodes used to manipulate fluids in microfluidic devices

  8. Diffractive element in extreme-UV lithography condenser

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Ray-Chaudhuri, Avijit (Livermore, CA)

    2001-01-01T23:59:59.000Z

    Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

  9. Jpn. J. Appl. Phys. Vol. 41 (2002) pp. 41014104 Part 1, No. 6B, June 2002

    E-Print Network [OSTI]

    Bokor, Jeffrey

    2002-01-01T23:59:59.000Z

    of Applied Physics "Actinic-only" Defects in Extreme Ultraviolet Lithography Mask Blanks --Native Defects, CA 94720, U.S.A. 2NTT Telecommunications Energy Laboratories, Atsugi, Kanagawa 243-0198, Japan 3 that native defects as small as 60 nm with only 3 nm height were detectable by the actinic tool. These defects

  10. Solving Maximum-Entropy Sampling Problems Using Factored Masks

    E-Print Network [OSTI]

    Samuel Burer

    2005-03-02T23:59:59.000Z

    Mar 2, 2005 ... Abstract: We present a practical approach to Anstreicher and Lee's masked spectral bound for maximum-entropy sampling, and we describe ...

  11. A masked spectral bound for maximum-entropy sampling

    E-Print Network [OSTI]

    Kurt Anstreicher

    2003-09-16T23:59:59.000Z

    Sep 16, 2003 ... Abstract: We introduce a new masked spectral bound for the maximum-entropy sampling problem. This bound is a continuous generalization of ...

  12. A laser triggered vacuum spark x-ray lithography source 

    E-Print Network [OSTI]

    Keating, Richard Allen

    1987-01-01T23:59:59.000Z

    was 50 cm. Obviously, this type of configurat, ion is totally impractical for a step and repeat system. Synchrotron radiation is being considered as an x-ray lithography source. Many laboratories are experi- menting with synchrotron sources. Also... for production of submicron geometries and improvements needed is presented. 1v ACKNOWLEDGMENT This thesis was made possible through the assistance of a number of people. Huang Wei Ling helped gather much of the data presented in this thesis. She also...

  13. Low Cost Lithography Tool for High Brightness LED Manufacturing

    SciTech Connect (OSTI)

    Andrew Hawryluk; Emily True

    2012-06-30T23:59:59.000Z

    The objective of this activity was to address the need for improved manufacturing tools for LEDs. Improvements include lower cost (both capital equipment cost reductions and cost-ofownership reductions), better automation and better yields. To meet the DOE objective of $1- 2/kilolumen, it will be necessary to develop these highly automated manufacturing tools. Lithography is used extensively in the fabrication of high-brightness LEDs, but the tools used to date are not scalable to high-volume manufacturing. This activity addressed the LED lithography process. During R&D and low volume manufacturing, most LED companies use contact-printers. However, several industries have shown that these printers are incompatible with high volume manufacturing and the LED industry needs to evolve to projection steppers. The need for projection lithography tools for LED manufacturing is identified in the Solid State Lighting Manufacturing Roadmap Draft, June 2009. The Roadmap states that Projection tools are needed by 2011. This work will modify a stepper, originally designed for semiconductor manufacturing, for use in LED manufacturing. This work addresses improvements to yield, material handling, automation and throughput for LED manufacturing while reducing the capital equipment cost.

  14. Superconducting x-ray lithography source Phase 1 (XLS) safety analysis report

    SciTech Connect (OSTI)

    Blumberg, L. (ed.)

    1990-07-01T23:59:59.000Z

    This paper discusses safety aspects associated with the superconducting x-ray lithography source. The policy, building systems safety and storage ring systems safety are specifically addressed. (LSP)

  15. Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics

    DOE Patents [OSTI]

    Ellingson, W.A.; Brada, M.P.

    1995-06-20T23:59:59.000Z

    A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser`s wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known ``feature masks`` of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects. 29 figs.

  16. Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics

    DOE Patents [OSTI]

    Ellingson, William A. (Naperville, IL); Brada, Mark P. (Goleta, CA)

    1995-01-01T23:59:59.000Z

    A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser's wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known "feature masks" of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects.

  17. Low thermal distortion extreme-UV lithography reticle

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2001-01-01T23:59:59.000Z

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  18. Low thermal distortion extreme-UV lithography reticle

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  19. Low thermal distortion Extreme-UV lithography reticle and method

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  20. Electrodeposition of nickel oxyhydroxide films through polymer masks

    SciTech Connect (OSTI)

    Yang, M.C.; Lin, C.K.; Su, C.L. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering

    1995-04-01T23:59:59.000Z

    Electrochromic materials have attracted much attention for devices including ``smart windows`` and displays. Nickel oxyhydroxide films were electrodeposited through gelatin masks, whose thicknesses may control the optical transmittances of the deposited electrochromic films. The difference of transmittance, {Delta}T{sub 540}, between bleaching and coloration states at wavelength of 540 nm has a linear relationship with the gelatin mask thickness. {Delta}T{sub 540} increased if nickel oxyhydroxide was prepared in agitated electrolyte. The electrodeposited films, prepared with gelatin masks, may have higher stability. These results showed the feasibility of fabricating an electrochromic device with a controlled image whose contrast and brightness are adjustable with potential or current.

  1. Computer-Aided Design for Microfluidic Chips Based on Multilayer Soft Lithography

    E-Print Network [OSTI]

    Rajamani, Sriram K.

    Computer-Aided Design for Microfluidic Chips Based on Multilayer Soft Lithography Nada Amin1 Abstract-- Microfluidic chips are emerging as a powerful platform for automating biology experiments automation techniques for microfluidic chips based on multilayer soft lithography. We focus our attention

  2. UV-LED LITHOGRAPHY FOR 3-D HIGH ASPECT RATIO MICROSTRUCTURE PATTERNING

    E-Print Network [OSTI]

    in microfabrication. Table 1 compares the performance of UV-LEDs with a mercury lamp for several key parametersUV-LED LITHOGRAPHY FOR 3-D HIGH ASPECT RATIO MICROSTRUCTURE PATTERNING Jungkwun `JK' Kim*, Seung of Technology, Atlanta, GA, USA ABSTRACT This paper presents a UV lithography method that utilizes a UV-LED

  3. A microfluidic microbial fuel cell fabricated by soft lithography Fang Qian a,b,

    E-Print Network [OSTI]

    A microfluidic microbial fuel cell fabricated by soft lithography Fang Qian a,b, , Zhen He c microfluidic microbial fuel cell (MFC) platform built by soft-lithography tech- niques. The MFC design includes a unique sub-5 lL polydimethylsiloxane soft chamber featuring carbon cloth electrodes and microfluidic

  4. header for SPIE use Fluoropolymers for 157nm Lithography: Optical Properties from VUV

    E-Print Network [OSTI]

    Rollins, Andrew M.

    new radiation damage mechanisms in previously accepted optical materials. For 157 nm pellicles, newheader for SPIE use Fluoropolymers for 157nm Lithography: Optical Properties from VUV Absorbance With the introduction of 157 nm as the next optical lithography wavelength, the need for new pellicle and photoresist

  5. Mask-assisted seeded growth of segmented metallic heteronanostructures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Crane, Cameron C.; Tao, Jing; Wang, Feng; Zhu, Yimei; Chen, Jingyi

    2014-12-04T23:59:59.000Z

    Controlling the deposition of exotic metals in the seeded growth of multi-metal nanostructures is challenging. This work describes a seeded growth method assisted by a mask for synthesis of segmented binary or ternary metal nanostructures. Silica is used as a mask to partially block the surface of a seed and a second metal is subsequently deposited on the exposed area, forming a bimetallic heterodimer. The initial demonstration was carried out on a Au seed, followed by deposition of Pd or Pt on the seed. It was found that Pd tends to spread out laterally on the seed while Pt inclinesmore »to grow vertically into branched topology on Au. Without removal of the SiO? mask, Pt could be further deposited on the unblocked Pd of the Pd-Au dimer to form a Pt-Pd-Au trimer. The mask-assisted seeded growth provides a general strategy to construct segmented metallic nanoarchitectures.« less

  6. SIGNAL MASKING IN GAUSSIAN CHANNELS John A. Quinn

    E-Print Network [OSTI]

    Edinburgh, University of

    and masking noise pollution. We present results as to how this can be done efficiently, assuming that we have. We also discuss the ap- plication of the theory to acoustic signals, where we consider aspects

  7. Mask-assisted seeded growth of segmented metallic heteronanostructures

    SciTech Connect (OSTI)

    Crane, Cameron C. [Univ. of Arkansas, Fayetteville, AR (United States); Tao, Jing [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, Feng [Univ. of Arkansas, Fayetteville, AR (United States); Zhu, Yimei [Brookhaven National Lab. (BNL), Upton, NY (United States); Chen, Jingyi [Univ. of Arkansas, Fayetteville, AR (United States)

    2014-12-04T23:59:59.000Z

    Controlling the deposition of exotic metals in the seeded growth of multi-metal nanostructures is challenging. This work describes a seeded growth method assisted by a mask for synthesis of segmented binary or ternary metal nanostructures. Silica is used as a mask to partially block the surface of a seed and a second metal is subsequently deposited on the exposed area, forming a bimetallic heterodimer. The initial demonstration was carried out on a Au seed, followed by deposition of Pd or Pt on the seed. It was found that Pd tends to spread out laterally on the seed while Pt inclines to grow vertically into branched topology on Au. Without removal of the SiO? mask, Pt could be further deposited on the unblocked Pd of the Pd-Au dimer to form a Pt-Pd-Au trimer. The mask-assisted seeded growth provides a general strategy to construct segmented metallic nanoarchitectures.

  8. Self-cleaning optic for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Klebanoff, Leonard E.; Stulen, Richard H.

    2003-12-16T23:59:59.000Z

    A multilayer reflective optic or mirror for lithographic applications, and particularly extreme ultraviolet (EUV) lithography, having a surface or "capping" layer which in combination with incident radiation and gaseous molecular species such as O.sub.2, H.sub.2, H.sub.2 O provides for continuous cleaning of carbon deposits from the optic surface. The metal capping layer is required to be oxidation resistant and capable of transmitting at least 90% of incident EUV radiation. Materials for the capping layer include Ru, Rh, Pd, Ir, Pt and Au and combinations thereof.

  9. Low-cost method for producing extreme ultraviolet lithography optics

    DOE Patents [OSTI]

    Folta, James A. (Livermore, CA); Montcalm, Claude (Fort Collins, CO); Taylor, John S. (Livermore, CA); Spiller, Eberhard A. (Mt. Kisco, NY)

    2003-11-21T23:59:59.000Z

    Spherical and non-spherical optical elements produced by standard optical figuring and polishing techniques are extremely expensive. Such surfaces can be cheaply produced by diamond turning; however, the roughness in the diamond turned surface prevent their use for EUV lithography. These ripples are smoothed with a coating of polyimide before applying a 60 period Mo/Si multilayer to reflect a wavelength of 134 .ANG. and have obtained peak reflectivities close to 63%. The savings in cost are about a factor of 100.

  10. A laser triggered vacuum spark x-ray lithography source

    E-Print Network [OSTI]

    Keating, Richard Allen

    1987-01-01T23:59:59.000Z

    ionized state or the physical processes occurring 15 in a high temperature plasma. There are many advantages to the use of the vacuum spark as an x-ray source; the simplicity of the machine is one. The x-ray output is within the range usable for x-ray... spark apparatus ha- been studied here to determine its applicability to x-ray lithography. A capacitor which stored approximately 3 KJ supplied most of the energy for the plasma. A Nd-YAG laser was used to supply electrons and metallic atoms...

  11. Bubble masks for time-encoded imaging of fast neutrons.

    SciTech Connect (OSTI)

    Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John; Sweany, Melinda; Throckmorton, Daniel J.

    2013-09-01T23:59:59.000Z

    Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is induced-typically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gaps-bubbles-propagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

  12. Organization of Block Copolymers using NanoImprint Lithography: Comparison of Theory and Experiments

    E-Print Network [OSTI]

    Xingkun Man; Daivd Andelman; Henri Orland; Pascal Thebault; Pang-Hung Liu; Patrick Guenoun; Jean Daillant; Stefan Landis

    2011-01-26T23:59:59.000Z

    We present NanoImprint lithography experiments and modeling of thin films of block copolymers (BCP). The NanoImprint lithography is used to align perpendicularly lamellar phases, over distances much larger than the natural lamellar periodicity. The modeling relies on self-consistent field calculations done in two- and three-dimensions. We get a good agreement with the NanoImprint lithography setups. We find that, at thermodynamical equilibrium, the ordered BCP lamellae are much better aligned than when the films are deposited on uniform planar surfaces.

  13. Automated real-time detection of defects during machining of ceramics

    DOE Patents [OSTI]

    Ellingson, W.A.; Sun, J.

    1997-11-18T23:59:59.000Z

    Apparatus for the automated real-time detection and classification of defects during the machining of ceramic components employs an elastic optical scattering technique using polarized laser light. A ceramic specimen is continuously moved while being machined. Polarized laser light is directed onto the ceramic specimen surface at a fixed position just aft of the machining tool for examination of the newly machined surface. Any foreign material near the location of the laser light on the ceramic specimen is cleared by an air blast. As the specimen is moved, its surface is continuously scanned by the polarized laser light beam to provide a two-dimensional image presented in real-time on a video display unit, with the motion of the ceramic specimen synchronized with the data acquisition speed. By storing known ``feature masks`` representing various surface and sub-surface defects and comparing measured defects with the stored feature masks, detected defects may be automatically characterized. Using multiple detectors, various types of defects may be detected and classified. 14 figs.

  14. Automated real-time detection of defects during machining of ceramics

    DOE Patents [OSTI]

    Ellingson, William A. (Naperville, IL); Sun, Jiangang (Westmont, IL)

    1997-01-01T23:59:59.000Z

    Apparatus for the automated real-time detection and classification of defects during the machining of ceramic components employs an elastic optical scattering technique using polarized laser light. A ceramic specimen is continuously moved while being machined. Polarized laser light is directed onto the ceramic specimen surface at a fixed position just aft of the machining tool for examination of the newly machined surface. Any foreign material near the location of the laser light on the ceramic specimen is cleared by an air blast. As the specimen is moved, its surface is continuously scanned by the polarized laser light beam to provide a two-dimensional image presented in real-time on a video display unit, with the motion of the ceramic specimen synchronized with the data acquisition speed. By storing known "feature masks" representing various surface and sub-surface defects and comparing measured defects with the stored feature masks, detected defects may be automatically characterized. Using multiple detectors, various types of defects may be detected and classified.

  15. Method for the protection of extreme ultraviolet lithography optics

    DOE Patents [OSTI]

    Grunow, Philip A.; Clift, Wayne M.; Klebanoff, Leonard E.

    2010-06-22T23:59:59.000Z

    A coating for the protection of optical surfaces exposed to a high energy erosive plasma. A gas that can be decomposed by the high energy plasma, such as the xenon plasma used for extreme ultraviolet lithography (EUVL), is injected into the EUVL machine. The decomposition products coat the optical surfaces with a protective coating maintained at less than about 100 .ANG. thick by periodic injections of the gas. Gases that can be used include hydrocarbon gases, particularly methane, PH.sub.3 and H.sub.2S. The use of PH.sub.3 and H.sub.2S is particularly advantageous since films of the plasma-induced decomposition products S and P cannot grow to greater than 10 .ANG. thick in a vacuum atmosphere such as found in an EUVL machine.

  16. Holographic illuminator for synchrotron-based projection lithography systems

    DOE Patents [OSTI]

    Naulleau, Patrick P.

    2005-08-09T23:59:59.000Z

    The effective coherence of a synchrotron beam line can be tailored to projection lithography requirements by employing a moving holographic diffuser and a stationary low-cost spherical mirror. The invention is particularly suited for use in an illuminator device for an optical image processing system requiring partially coherent illumination. The illuminator includes: (1) a synchrotron source of coherent or partially coherent radiation which has an intrinsic coherence that is higher than the desired coherence, (2) a holographic diffuser having a surface that receives incident radiation from said source, (3) means for translating the surface of the holographic diffuser in two dimensions along a plane that is parallel to the surface of the holographic diffuser wherein the rate of the motion is fast relative to integration time of said image processing system; and (4) a condenser optic that re-images the surface of the holographic diffuser to the entrance plane of said image processing system.

  17. An Eight-Octant Phase-Mask Coronagraph

    E-Print Network [OSTI]

    Murakami, N; Baba, N; Nishikawa, J; Tamura, M; Hashimoto, N; Abe, L

    2008-01-01T23:59:59.000Z

    We present numerical simulations and laboratory experiments on an eight-octant phase-mask (EOPM) coronagraph. The numerical simulations suggest that an achievable contrast for the EOPM coronagraph can be greatly improved as compared to that of a four-quadrant phase-mask (FQPM) coronagraph for a partially resolved star. On-sky transmission maps reveal that the EOPM coronagraph has relatively high optical throughput, a small inner working angle and large discovery space. We have manufactured an eight-segment phase mask utilizing a nematic liquid-crystal device, which can be easily switched between the FQPM and the EOPM modes. The laboratory experiments demonstrate that the EOPM coronagraph has a better tolerance of the tip-tilt error than the FQPM one. We also discuss feasibility of a fully achromatic and high-throughput EOPM coronagraph utilizing a polarization interferometric technique.

  18. An Eight-Octant Phase-Mask Coronagraph

    E-Print Network [OSTI]

    N. Murakami; R. Uemura; N. Baba; J. Nishikawa; M. Tamura; N. Hashimoto; L. Abe

    2008-09-09T23:59:59.000Z

    We present numerical simulations and laboratory experiments on an eight-octant phase-mask (EOPM) coronagraph. The numerical simulations suggest that an achievable contrast for the EOPM coronagraph can be greatly improved as compared to that of a four-quadrant phase-mask (FQPM) coronagraph for a partially resolved star. On-sky transmission maps reveal that the EOPM coronagraph has relatively high optical throughput, a small inner working angle and large discovery space. We have manufactured an eight-segment phase mask utilizing a nematic liquid-crystal device, which can be easily switched between the FQPM and the EOPM modes. The laboratory experiments demonstrate that the EOPM coronagraph has a better tolerance of the tip-tilt error than the FQPM one. We also discuss feasibility of a fully achromatic and high-throughput EOPM coronagraph utilizing a polarization interferometric technique.

  19. BAYESIAN INSIGHTS ON DISCLOSURE LIMITATION: MASK OR IMPUTE?

    SciTech Connect (OSTI)

    S. KELLER-MCNULTY; G. DUNCAN

    2000-10-01T23:59:59.000Z

    Statistical agencies seek to disseminate useful data while keeping low the risk of statistical confidentiality disclosure. Recognizing that reidentification of data is generally inadequate to protect its confidentiality against attack by a data snooper, agencies restrict the data they release for general use. Typically, these restricted data procedures have involved transformation or masking of the original, collected data through such devices as adding noise, topcoding, data swapping, and recoding. Recently, proposals have been put forth for the release of synthetic data, simulated from models constructed from the original data. This paper gives a framework for the comparison of masking and synthetic data as two approaches to disclosure limitation. Particular attention is paid to data utility and disclosure risk. Examples of instantiation of masking and of synthetic data construction are provided to illustrate the concepts. Particular attention is paid to data swapping. Insights drawn from the Bayesian paxadigm are provided.

  20. System for generating two-dimensional masks from a three-dimensional model using topological analysis

    DOE Patents [OSTI]

    Schiek, Richard (Albuquerque, NM)

    2006-06-20T23:59:59.000Z

    A method of generating two-dimensional masks from a three-dimensional model comprises providing a three-dimensional model representing a micro-electro-mechanical structure for manufacture and a description of process mask requirements, reducing the three-dimensional model to a topological description of unique cross sections, and selecting candidate masks from the unique cross sections and the cross section topology. The method further can comprise reconciling the candidate masks based on the process mask requirements description to produce two-dimensional process masks.

  1. Development of a microfluidic device for patterning multiple species by scanning probe lithography

    E-Print Network [OSTI]

    Rivas Cardona, Juan Alberto

    2009-06-02T23:59:59.000Z

    Scanning Probe Lithography (SPL) is a versatile nanofabrication platform that leverages microfluidic “ink” delivery systems with Scanning Probe Microscopy (SPM) for generating surface-patterned chemical functionality on the sub-100 nm length scale...

  2. Sub-10-nm electron-beam lithography for templated placement of colloidal quantum dots

    E-Print Network [OSTI]

    Manfrinato, Vitor Riseti

    2011-01-01T23:59:59.000Z

    This thesis presents the investigation of resolution limits of electron-beam lithography (EBL) at the sub-10-nm scale. EBL patterning was investigated at low electron energy (2 keV) in a converted scanning electron microscope ...

  3. Real-time spatial-phase-locked electron-beam lithography

    E-Print Network [OSTI]

    Zhang, Feng, 1973-

    2005-01-01T23:59:59.000Z

    The ability of electron-beam lithography (EBL) to create sub-10-nm features with arbitrary geometry makes it a critical tool in many important applications in nanoscale science and technology. The conventional EBL system ...

  4. The development of a prototype Zone-Plate-Array Lithography (ZPAL) system

    E-Print Network [OSTI]

    Patel, Amil Ashok, 1979-

    2004-01-01T23:59:59.000Z

    The research presented in this paper aims to build a Zone-Plate-Array Lithography (ZPAL) prototype tool that will demonstrate the high-resolution, parallel patterning capabilities of the architecture. The experiment will ...

  5. Contact region fidelity, sensitivity, and control in roll-based soft lithography

    E-Print Network [OSTI]

    Petrzelka, Joseph E

    2012-01-01T23:59:59.000Z

    Soft lithography is a printing process that uses small features on an elastomeric stamp to transfer micron and sub-micron patterns to a substrate. Translating this lab scale process to a roll-based manufacturing platform ...

  6. Resolution Limits of Electron-Beam Lithography toward the Atomic Scale

    E-Print Network [OSTI]

    Zhang, Lihua

    We investigated electron-beam lithography with an aberration-corrected scanning transmission electron microscope. We achieved 2 nm isolated feature size and 5 nm half-pitch in hydrogen silsesquioxane resist. We also analyzed ...

  7. Fabrication of ZnO photonic crystals by nanosphere lithography using inductively coupled-plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the ZnO/GaN heterojunction light emitting diodes

    SciTech Connect (OSTI)

    Chen, Shr-Jia; Chang, Chun-Ming; Kao, Jiann-Shiun; Chen, Fu-Rong; Tsai, Chuen-Horng [Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, 300 Taiwan (China); Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China)

    2010-07-15T23:59:59.000Z

    This article reports fabrication of n-ZnO photonic crystal/p-GaN light emitting diode (LED) by nanosphere lithography to further booster the light efficiency. In this article, the fabrication of ZnO photonic crystals is carried out by nanosphere lithography using inductively coupled plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the n-ZnO/p-GaN heterojunction LEDs. The CH{sub 4}/H{sub 2}/Ar mixed gas gives high etching rate of n-ZnO film, which yields a better surface morphology and results less plasma-induced damages of the n-ZnO film. Optimal ZnO lattice parameters of 200 nm and air fill factor from 0.35 to 0.65 were obtained from fitting the spectrum of n-ZnO/p-GaN LED using a MATLAB code. In this article, we will show our recent result that a ZnO photonic crystal cylinder has been fabricated using polystyrene nanosphere mask with lattice parameter of 200 nm and radius of hole around 70 nm. Surface morphology of ZnO photonic crystal was examined by scanning electron microscope.

  8. Ga lithography in sputtered niobium for superconductive micro and nanowires

    SciTech Connect (OSTI)

    Henry, M. David; Wolfley, Steve; Monson, Todd; Lewis, Rupert [Sandia National Labs, MESA Facility, P.O. Box 5800, Albuquerque, New Mexico 87185-1084 (United States)

    2014-08-18T23:59:59.000Z

    This work demonstrates the use of focused ion beam (FIB) implanted Ga as a lithographic mask for plasma etching of Nb films. Using a highly collimated Ga beam of a FIB, Nb is implanted 12?nm deep with a 14?nm thick Ga layer providing etch selectivity better than 15:1 with fluorine based etch chemistry. Implanted square test patterns, both 10??m by 10??m and 100??m by 100??m, demonstrate that doses above than 7.5?×?10{sup 15?}cm{sup ?2} at 30?kV provide adequate mask protection for a 205?nm thick, sputtered Nb film. The resolution of this dry lithographic technique is demonstrated by fabrication of nanowires 75?nm wide by 10??m long connected to 50??m wide contact pads. The residual resistance ratio of patterned Nb films was 3. The superconducting transition temperature (T{sub c})?=?7.7?K was measured using a magnetic properties measurement system. This nanoscale, dry lithographic technique was extended to sputtered TiN and Ta here and could be used on other fluorine etched superconductors such as NbN, NbSi, and NbTi.

  9. Adaptive Streaming and Rendering of Large Terrains using Strip Masks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Adaptive Streaming and Rendering of Large Terrains using Strip Masks Joachim Pouderoux Jean-Eudes Marvie IPARLA Project (LaBRI - INRIA Futurs) University of Bordeaux, France Abstract Terrain rendering is an important factor in the rendering of virtual scenes. If they are large and detailed, digital terrains can

  10. The rhetorical mask as an aid to composition

    E-Print Network [OSTI]

    Bovey, Shirley Ellen

    1972-01-01T23:59:59.000Z

    , it can be demonstrated that professional writers do use a rhetorical mask. A short essay from The Norton Reader, "Pop Angler, " will be used to illustrate this idea; the opening paragraphs are quoted in order to show that the persona is established...

  11. BAYESIAN RELIABILITY MODELING FOR MASKED SYSTEM LIFETIME DATA

    E-Print Network [OSTI]

    Kuo, Lynn

    supported by Korea Science and Engineering Foundation 971­0105­027­2. 1 #12; reliability of the components of Statistics, University of Connecticut, Storrs, CT 06269­3120, USA Tae Young YANG y Department of Mathematics consider various probability models for the conditional masking probabilities that identify the set

  12. Simultaneous Feature Extraction and Selection Using a Masking Genetic Algorithm

    E-Print Network [OSTI]

    1 Simultaneous Feature Extraction and Selection Using a Masking Genetic Algorithm Michael L. Raymer: identification of functional water molecules bound to protein surfaces, and diagnosis of thyroid deficiency of feature extraction ­ defining new features in terms of the original feature set to facilitate more

  13. Masking Property of Quantum Random Cipher with Phase Mask Encryption -Towards Quantum Enigma Cipher-

    E-Print Network [OSTI]

    Masaki Sohma; Osamu Hirota

    2014-04-18T23:59:59.000Z

    The security analysis of physical encryption protocol based on coherent pulse position modulation(CPPM) originated by Yuen is one of the most interesting topics in the study of cryptosystem with a security level beyond the Shannon limit. Although the implementation of CPPM scheme has certain difficulty, several methods have been proposed recently. This paper deals with the CPPM encryption in terms of symplectic transformation, which includes a phase mask encryption as a special example, and formulates a unified security analysis for such encryption schemes. Specifically, we give a lower bound of Eve's symbol error probability using reliability function theory to ensure that our proposed system exceeds the Shannon limit. Then we assume the secret key is given to Eve after her heterodyne measurement. Since this assumption means that Eve has a great advantage in the sense of the conventional cryptography, the lower bound of her error indeed ensures the security level beyond the Shannon limit. In addition, we show some numerical examples of the security performance.

  14. Analysis of Optics and Mask Contamination in SEMATECH EUV Micro-Exposure Tools

    E-Print Network [OSTI]

    Wuest, Andrea

    2008-01-01T23:59:59.000Z

    Analysis of Optics and Mask Contamination in SEMATECHMioro^Exposure Tools IEUVI Optics Contamination/Lifetime TWG

  15. A next-generation EUV Fresnel zoneplate mask-imaging microscope

    E-Print Network [OSTI]

    Goldberg, Kenneth A.

    2012-01-01T23:59:59.000Z

    A next-generation EUV Fresnel zoneplate mask-imaginghigh-magnification all-EUV Fresnel zoneplate microscope, the

  16. Disposable colorimetric carbon dioxide detector use as an indicator of a patent airway during noninvasive mask ventilation

    E-Print Network [OSTI]

    Leone, T A; Lange, A; Rich, W; Finer, N N

    2006-01-01T23:59:59.000Z

    During Noninvasive Mask Ventilation Tina A. Leone, Allisonduring bag and mask ventilation and en- courage others toposi- tive pressure ventilation in preterm babies ventilated

  17. Affine Defects and Gravitation

    E-Print Network [OSTI]

    R. J. Petti

    2014-12-12T23:59:59.000Z

    We argue that the structure general relativity (GR) as a theory of affine defects is deeper than the standard interpretation as a metric theory of gravitation. Einstein-Cartan theory (EC), with its inhomogenous affine symmetry, should be the standard-bearer for GR-like theories. A discrete affine interpretation of EC (and gauge theory) yields topological definitions of momentum and spin (and Yang Mills current), and their conservation laws become discrete topological identities. Considerations from quantum theory provide evidence that discrete affine defects are the physical foundation for gravitation.

  18. Proceedings of NAMRI/SME, Vol. 39, 2011 Additive Manufacturing based on Optimized Mask Video

    E-Print Network [OSTI]

    Chen, Yong

    Proceedings of NAMRI/SME, Vol. 39, 2011 Additive Manufacturing based on Optimized Mask Video@usc.edu, (213) 740-7829 ABSTRACT Additive manufacturing (AM) processes based on mask image projection and resolution of built components. KEYWORDS Additive manufacturing, Solid freeform fabrication, Mask image

  19. ROBUST CONTENT-BASED VIDEO WATERMARKING EXPLOITING MOTION ENTROPY MASKING EFFECT

    E-Print Network [OSTI]

    Reif, Rafael

    ROBUST CONTENT-BASED VIDEO WATERMARKING EXPLOITING MOTION ENTROPY MASKING EFFECT Amir Houmansadr: Digital watermarking, Video sequence, Entropy masking. Abstract: A major class of image and video, a content-based video watermarking scheme is developed and the concept of entropy masking effect is employed

  20. Discrete torsion defects

    E-Print Network [OSTI]

    Ilka Brunner; Nils Carqueville; Daniel Plencner

    2014-09-15T23:59:59.000Z

    Orbifolding two-dimensional quantum field theories by a symmetry group can involve a choice of discrete torsion. We apply the general formalism of `orbifolding defects' to study and elucidate discrete torsion for topological field theories. In the case of Landau-Ginzburg models only the bulk sector had been studied previously, and we re-derive all known results. We also introduce the notion of `projective matrix factorisations', show how they naturally describe boundary and defect sectors, and we further illustrate the efficiency of the defect-based approach by explicitly computing RR charges. Roughly half of our results are not restricted to Landau-Ginzburg models but hold more generally, for any topological field theory. In particular we prove that for a pivotal bicategory, any two objects of its orbifold completion that have the same base are orbifold equivalent. Equivalently, from any orbifold theory (including those based on nonabelian groups) the original unorbifolded theory can be obtained by orbifolding via the `quantum symmetry defect'.

  1. Fundamentals of embossing nanoimprint lithography in polymer substrates.

    SciTech Connect (OSTI)

    Simmons, Blake Alexander; King, William P. (University of Illinois, Urbana IL)

    2011-02-01T23:59:59.000Z

    The convergence of micro-/nano-electromechanical systems (MEMS/NEMS) and biomedical industries is creating a need for innovation and discovery around materials, particularly in miniaturized systems that use polymers as the primary substrate. Polymers are ubiquitous in the microelectronics industry and are used as sensing materials, lithography tools, replication molds, microfluidics, nanofluidics, and biomedical devices. This diverse set of operational requirements dictates that the materials employed must possess different properties in order to reduce the cost of production, decrease the scale of devices to the appropriate degree, and generate engineered devices with new functional properties at cost-competitive levels of production. Nanoscale control of polymer deformation at a massive scale would enable breakthroughs in all of the aforementioned applications, but is currently beyond the current capabilities of mass manufacturing. This project was focused on developing a fundamental understanding of how polymers behave under different loads and environments at the nanoscale in terms of performance and fidelity in order to fill the most critical gaps in our current knowledgebase on this topic.

  2. Virtually distortion-free imaging system for large field, high resolution lithography

    DOE Patents [OSTI]

    Hawryluk, A.M.; Ceglio, N.M.

    1993-01-05T23:59:59.000Z

    Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position.

  3. X-ray mask and method for making

    DOE Patents [OSTI]

    Morales, Alfredo M.

    2004-10-26T23:59:59.000Z

    The present invention describes a method for fabricating an x-ray mask tool which is a contact lithographic mask which can provide an x-ray exposure dose which is adjustable from point-to-point. The tool is useful in the preparation of LIGA plating molds made from PMMA, or similar materials. In particular the tool is useful for providing an ability to apply a graded, or "stepped" x-ray exposure dose across a photosensitive substrate. By controlling the x-ray radiation dose from point-to-point, it is possible to control the development process for removing exposed portions of the substrate; adjusting it such that each of these portions develops at a more or less uniformly rate regardless of feature size or feature density distribution.

  4. Electron tomography of defects

    E-Print Network [OSTI]

    Sharp, Joanne

    2010-10-12T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . 36 2.6 Limitations of electron tomography . . . . . . . . . . . . . . . 37 2.6.1 The missing wedge . . . . . . . . . . . . . . . . . . . . 37 2.6.2 Minimum reliable spacing of features . . . . . . . . . . 39 3 Tomography of dislocations using weak... ELECTRON TOMOGRAPHY OF DEFECTS This dissertation is submitted for the degree of Doctor of Philosophy by Joanne Sharp Of Wolfson College Submitted 26th April 2010 Acknowledgements This dissertation is the result of my own work and includes nothing...

  5. Defect mapping system

    DOE Patents [OSTI]

    Sopori, B.L.

    1995-04-11T23:59:59.000Z

    Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities. 20 figures.

  6. UV-nanoimprint lithography and large area roll-to-roll texturization with hyperbranched polymer nanocomposites for light-trapping applications$

    E-Print Network [OSTI]

    UV-nanoimprint lithography and large area roll-to-roll texturization with hyperbranched polymer nanoimprint lithography Light-trapping Roll-to-roll Amorphous silicon a b s t r a c t Light-trapping textures were produced in hyperbranched polymer (HBP) silica nanocomposites using a UV-nanoimprint lithography

  7. Selectively patterning polymer opal films via microimprint lithography

    E-Print Network [OSTI]

    Ding, Tao; Zhao, Qibin; Smoukov, Stoyan; Baumberg, Jeremy J.

    2014-09-01T23:59:59.000Z

    -imprinting these solid flexible films, the PEA matrix containing the hard spherical particles deforms into negative patterns of the stamp resulting in a rearrangement of the spheres as shown in Scheme 1. The intrusion of the hard posts squeezes the POF laterally... reflectivities drop to ~30%, which may arise because of non-homogeneous flows or the introduction of defects during squeezing and compression. For the sheared region II, squeezing might be expected to expand the lattice spacing vertically, but although...

  8. Corner Rounding in Photoresists for Extreme Ultraviolet Lithography

    SciTech Connect (OSTI)

    Anderson, Christopher N.; Naulleau, Patrick; Deng, Yunfei; Wallow, Thomas

    2008-06-01T23:59:59.000Z

    Deprotection blur in EUV resists fundamentally limits the smallest sized dense features that can be patterned in a single exposure and development step. Several metrics have recently been developed to explore the ways that different resist and process parameters affect the deprotection blur in EUV resists. One of these metrics is based on the imaging fidelity of a sharp corner on a large feature. As this metric has involved the close inspection of printing fidelity of corner features, it has brought attention to an interesting phenomena: corners print differently whether or not the remaining resist edge contains 270 degrees of resist or 90 degrees of resist. Here we present experimental data across a wide sampling of leading resists to show this effect is real and reproducible. They provide aerial image modeling results assuming thin and realistic mask models that show no corner bias between the aerial images in the 90-degree and 270-degree configurations. They also compare modeled patterning results assuming several resist models including the single blur, dual blur, and Prolith models, none of which reproduce the corner biasing that is observed experimentally.

  9. Extreme ultraviolet lithography: A few more pieces of the puzzle

    SciTech Connect (OSTI)

    Anderson, Christopher N.

    2009-05-20T23:59:59.000Z

    The work described in this dissertation has improved three essential components of extreme ultraviolet (EUV) lithography: exposure tools, photoresist, and metrology. Exposure tools. A field-averaging illumination stage is presented that enables nonuniform, high-coherence sources to be used in applications where highly uniform illumination is required. In an EUV implementation, it is shown that the illuminator achieves a 6.5% peak-to-valley intensity variation across the entire design field of view. In addition, a design for a stand-alone EUV printing tool capable of delivering 15 nm half-pitch sinusoidal fringes with available sources, gratings and nano-positioning stages is presented. It is shown that the proposed design delivers a near zero line-edge-rougness (LER) aerial image, something extremely attractive for the application of resist testing. Photoresist. Two new methods of quantifying the deprotection blur of EUV photoresists are described and experimentally demonstrated. The deprotection blur, LER, and sensitivity parameters of several EUV photoresists are quantified simultaneously as base weight percent, photoacid generator (PAG) weight percent, and post-exposure bake (PEB) temperature are varied. Two surprising results are found: (1) changing base weight percent does not significantly affect the deprotection blur of EUV photoresist, and (2) increasing PAG weight percent can simultaneously reduce LER and E-size in EUV photoresist. The latter result motivates the development of an EUV exposure statistics model that includes the effects of photon shot noise, the PAG spatial distribution, and the changing of the PAG distribution during the exposure. In addition, a shot noise + deprotection blur model is used to show that as deprotection blur becomes large relative to the size of the printed feature, LER reduction from improved counting statistics becomes dominated by an increase in LER due to reduced deprotection contrast. Metrology. Finally, this dissertation describes MOSAIC, a new wavefront metrology that enables complete wavefront recovery from print or aerial image based measurements. This new technique, based on measuring the local focal length of the optic at sampled positions in the pupil, recovers the curvature of the aberration and uses the curvature to recover the aberration itself. In a modeled EUV implementation, MOSAIC is shown to recover the SEMATECH Berkeley MET wavefront with a 4.2% RMS error: a 4% improvement over the reported errors of the original lateral shearing interferometry wavefront measurement.

  10. Who named the quantum defect?

    SciTech Connect (OSTI)

    Rau, A.R.P. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; Inokuti, M. [Argonne National Lab., IL (United States). Physics Div.

    1997-08-01T23:59:59.000Z

    The notion of the quantum defect is important in atomic and molecular spectroscopy and also in unifying spectroscopy with collision theory. In the latter context, the quantum defect may be viewed as an ancestor of the phase shift. However, the origin of the term quantum defect does not seem to be explained in standard textbooks. It occurred in a 1921 paper by Schroedinger, preceding quantum mechanics, yet giving the correct meaning as an index of the short-range interactions with the core of an atom. The authors present the early history of the quantum-defect idea, and sketch its recent developments.

  11. Ice-assisted electron beam lithography of graphene Jules A Gardener1

    E-Print Network [OSTI]

    1 Ice-assisted electron beam lithography of graphene Jules A Gardener1 and Jene A Golovchenko1 with a thin ice layer. The irradiated ice plays a crucial role in the process by providing activated species that locally remove graphene from a silicon dioxide substrate. After patterning the graphene, the ice resist

  12. Flexible CO2 laser system for fundamental research related to an extreme ultraviolet lithography source

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    Flexible CO2 laser system for fundamental research related to an extreme ultraviolet lithography 2009; published online 10 December 2009 A CO2 laser system with flexible parameters was developed 1010 W/cm2 . Utilizing this CO2 MOPA laser system, high conversion efficiency from laser to in-band 2

  13. A novel lithography technique for formation of large areas of uniform nanostructures

    E-Print Network [OSTI]

    Shahriar, Selim

    such as plasmonics, sensors, storage devices, solar cells, nano-filtration and artificial kidneys require applications such as surface plasmonics[1] , data storage[2] , optoelectronic devices[3] , and nanoA novel lithography technique for formation of large areas of uniform nanostructures Wei Wu

  14. Magnetic anisotropy in a permalloy microgrid fabricated by near-field optical lithography

    SciTech Connect (OSTI)

    Li, S. P.; Lebib, A.; Peyrade, D.; Natali, M.; Chen, Y.; Lew, W. S.; Bland, J. A. C.

    2001-07-01T23:59:59.000Z

    We report the fabrication and magnetic properties of permalloy microgrids prepared by near-field optical lithography and characterized using high-sensitivity magneto-optical Kerr effect techniques. A fourfold magnetic anisotropy induced by the grid architecture is identified. {copyright} 2001 American Institute of Physics.

  15. Pure Boron-Doped Photodiodes: a Solution for Radiation Detection in EUV Lithography

    E-Print Network [OSTI]

    Technische Universiteit Delft

    Pure Boron-Doped Photodiodes: a Solution for Radiation Detection in EUV Lithography F. Sarubbi, L for radiation detection in the extreme-ultra-violet (EUV) spectral range. Outstanding electrical and optical has triggered a growing interest in UV radiation detection at wavelengths between 10 nm and 200 nm

  16. Fabrication of magnetic microfiltration systems using soft lithography Tao Deng, Mara Prentiss,a)

    E-Print Network [OSTI]

    Prentiss, Mara

    . The combination of microtransfer molding--a soft lithography technique--and electrodeposition generated nickel, Massachusetts 02138 Received 9 August 2001; accepted for publication 9 November 2001 Arrays of nickel posts were field from an external, permanent, neodymium­iron­boron magnet, these nickel posts generated strong

  17. Wafer-Scale Fabrication of Nanofluidic Arrays and Networks Using Nanoimprint Lithography and Lithographically Patterned Nanowire

    E-Print Network [OSTI]

    Wafer-Scale Fabrication of Nanofluidic Arrays and Networks Using Nanoimprint Lithography of nanofluidic channels (up to 1 mm in length) filled with solutions of either fluorescent dye or 20 nm diameter-replica process was also used to create a large two-dimensional network of crossed nanofluidic channels. Large

  18. Toward Optimized Light Utilization in Nanowire Arrays Using Scalable Nanosphere Lithography and Selected Area Growth

    E-Print Network [OSTI]

    Zhou, Chongwu

    can have application in high-throughput and low-cost optoelectronic devices, including solar cellsToward Optimized Light Utilization in Nanowire Arrays Using Scalable Nanosphere Lithography promising results when used to fabricate light emitters6-10 and photovoltaic devices.11-15 The small contact

  19. Room-temperature Si single-electron memory fabricated by nanoimprint lithography

    E-Print Network [OSTI]

    , Haixiong Ge, Christopher Keimel, and Stephen Y. Chou NanoStructure Laboratory, Department of Electrical using nanoimprint lithography NIL . The devices consist of a narrow channel metal­ oxide­semiconductor field-effect transistor and a sub-10-nm storage dot, which is located between the channel and the gate

  20. Methane Digesters and Biogas Recovery - Masking the Environmental Consequences of Industrial Concentrated Livestock Production

    E-Print Network [OSTI]

    Di Camillo, Nicole G.

    2011-01-01T23:59:59.000Z

    Methane Digesters and Biogas Recovery-Masking theII. METHANE DIGESTERS AND BIOGAs RECOVERY- IN THE2011] METHANE DIGESTERS AND BIOGAS RECOVERY methane, and 64%

  1. Carbon contamination of extreme ultraviolet (EUV) mask and its effect on imaging

    E-Print Network [OSTI]

    Fan, Yu-Jen

    2009-01-01T23:59:59.000Z

    induced carbon contamination of extreme ultraviolet optics."potential LWR due to the contamination topography may be anet aI. , "Accelerated contamination testing of EUV masks."

  2. Analysis of Optics and Mask Contamination in SEMATECH EUV Micro-Exposure Tools

    E-Print Network [OSTI]

    Wuest, Andrea

    2008-01-01T23:59:59.000Z

    of Optics and Mask Contamination in SEMATECH EUV MioroTools IEUVI Optics Contamination/Lifetime TWG Sapporo,of spot inside visible contamination. sputter time (min) c

  3. Methane Digesters and Biogas Recovery - Masking the Environmental Consequences of Industrial Concentrated Livestock Production

    E-Print Network [OSTI]

    Di Camillo, Nicole G.

    2011-01-01T23:59:59.000Z

    DIGESTERS AND BIOGAS RECOVERY Digesters Do Not Address theMethane Digesters and Biogas Recovery-Masking theII. METHANE DIGESTERS AND BIOGAs RECOVERY- IN THE

  4. Methane Digesters and Biogas Recovery - Masking the Environmental Consequences of Industrial Concentrated Livestock Production

    E-Print Network [OSTI]

    Di Camillo, Nicole G.

    2011-01-01T23:59:59.000Z

    Methane Digesters and Biogas Recovery-Masking theII. METHANE DIGESTERS AND BIOGAs RECOVERY- IN THEA. Digesters Have Received Attention for Their Potential to

  5. The Mask Manufacturing Unit (MMU), one of the three main components of the

    E-Print Network [OSTI]

    Liske, Jochen

    of the VIRMOS Laser Mask Manufacturing Unit (MMU) at Paranal G. AVILA1, G. CONTI2, E. MATTAINI2, L. CHIAPPETTI 2 under a 16 bar compressed air jet. The laser system (manufactured by the German LPKF company) is also1 The Mask Manufacturing Unit (MMU), one of the three main components of the VIRMOS project, has

  6. Carbon Contamination Topography Analysis of EUV Masks Yu-Jen Fan1

    E-Print Network [OSTI]

    Carbon Contamination Topography Analysis of EUV Masks Yu-Jen Fan1 , Leonid Yankulin1 , Petros ABSTRACT The impact of carbon contamination on extreme ultraviolet (EUV) masks is significant due to throughput loss and potential effects on imaging performance. Current carbon contamination research primarily

  7. Graphene Edge Lithography Guibai Xie, Zhiwen Shi, Rong Yang, Donghua Liu, Wei Yang, Meng Cheng, Duoming Wang, Dongxia Shi,

    E-Print Network [OSTI]

    Zhang, Guangyu

    Graphene Edge Lithography Guibai Xie, Zhiwen Shi, Rong Yang, Donghua Liu, Wei Yang, Meng Cheng: Fabrication of graphene nanostructures is of importance for both investigating their intrinsic physical approach for graphene nanostructures. Compared with conventional lithographic fabrication techniques

  8. Update on the SEMATECH 0.5 NA Extreme-Ultraviolet Lithography (EUVL) Microfield Exposure Tool (MET)

    E-Print Network [OSTI]

    Cummings, Kevin

    2014-01-01T23:59:59.000Z

    eld Exposure Tools with 0.5 NA,” Proc. SPIE TBP (2014) [6]microexposure tool at 0.5 NA for sub-16 nm lithography,&Update on the SEMATECH 0.5 NA Extreme Ultraviolet

  9. Design and analysis of a scanning beam interference lithography system for patterning gratings with nanometer-level distortions

    E-Print Network [OSTI]

    Konkola, Paul Thomas, 1973-

    2003-01-01T23:59:59.000Z

    This thesis describes the design and analysis of a system for patterning large-area gratings with nanometer level phase distortions. The novel patterning method, termed scanning beam interference lithography (SBIL), uses ...

  10. Energy Dissipation and Defect Generation for Nanocrystalline...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Defect Generation for Nanocrystalline Silicon Carbide. Abstract: Large-scale molecular dynamics simulations have been employed to study defect generation and primary damage...

  11. ATOMIC FORCE LITHOGRAPHY OF NANO/MICROFLUIDIC CHANNELS FOR VERIFICATION AND MONITORING OF AQUEOUS SOLUTIONS

    SciTech Connect (OSTI)

    Mendez-Torres, A.; Torres, R.; Lam, P.

    2011-07-15T23:59:59.000Z

    The growing interest in the physics of fluidic flow in nanoscale channels, as well as the possibility for high sensitive detection of ions and single molecules is driving the development of nanofluidic channels. The enrichment of charged analytes due to electric field-controlled flow and surface charge/dipole interactions along the channel can lead to enhancement of sensitivity and limits-of-detection in sensor instruments. Nuclear material processing, waste remediation, and nuclear non-proliferation applications can greatly benefit from this capability. Atomic force microscopy (AFM) provides a low-cost alternative for the machining of disposable nanochannels. The small AFM tip diameter (< 10 nm) can provide for features at scales restricted in conventional optical and electron-beam lithography. This work presents preliminary results on the fabrication of nano/microfluidic channels on polymer films deposited on quartz substrates by AFM lithography.

  12. ATOMIC FORCE LITHOGRAPHY OF NANO MICROFLUIDIC CHANNELS FOR VERIFICATION AND MONITORING IN AQUEOUS SOLUTIONS

    SciTech Connect (OSTI)

    Torres, R.; Mendez-Torres, A.; Lam, P.

    2011-06-09T23:59:59.000Z

    The growing interest in the physics of fluidic flow in nanoscale channels, as well as the possibility for high sensitive detection of ions and single molecules is driving the development of nanofluidic channels. The enrichment of charged analytes due to electric field-controlled flow and surface charge/dipole interactions along the channel can lead to enhancement of sensitivity and limits-of-detection in sensor instruments. Nuclear material processing, waste remediation, and nuclear non-proliferation applications can greatly benefit from this capability. Atomic force microscopy (AFM) provides a low-cost alternative for the machining of disposable nanochannels. The small AFM tip diameter (< 10 nm) can provide for features at scales restricted in conventional optical and electron-beam lithography. This work presents preliminary results on the fabrication of nano/microfluidic channels on polymer films deposited on quartz substrates by AFM lithography.

  13. Topological Defects from the Multiverse

    E-Print Network [OSTI]

    Zhang, Jun; Garriga, Jaume; Vilenkin, Alexander

    2015-01-01T23:59:59.000Z

    Many theories of the early universe predict the existence of a multiverse where bubbles continuously nucleate giving rise to observers in their interior. In this paper, we point out that topological defects of several dimensionalities will also be produced in de Sitter like regions of the multiverse. In particular, defects could be spontaneously nucleated in our parent vacuum. We study the evolution of these defects as they collide with and propagate inside of our bubble. We estimate the present distribution of defects in the observable part of the universe. The expected number of such nearby defects turns out to be quite small, even for the highest nucleation rate. We also study collisions of strings and domain walls with our bubble in our past light cone. We obtain simulated full-sky maps of the loci of such collisions, and find their angular size distribution. Similarly to what happens in the case of bubble collisions, the prospect of detecting any collisions of our bubble with ambient defects is greatly e...

  14. Topological Defects from the Multiverse

    E-Print Network [OSTI]

    Jun Zhang; Jose J. Blanco-Pillado; Jaume Garriga; Alexander Vilenkin

    2015-01-22T23:59:59.000Z

    Many theories of the early universe predict the existence of a multiverse where bubbles continuously nucleate giving rise to observers in their interior. In this paper, we point out that topological defects of several dimensionalities will also be produced in de Sitter like regions of the multiverse. In particular, defects could be spontaneously nucleated in our parent vacuum. We study the evolution of these defects as they collide with and propagate inside of our bubble. We estimate the present distribution of defects in the observable part of the universe. The expected number of such nearby defects turns out to be quite small, even for the highest nucleation rate. We also study collisions of strings and domain walls with our bubble in our past light cone. We obtain simulated full-sky maps of the loci of such collisions, and find their angular size distribution. Similarly to what happens in the case of bubble collisions, the prospect of detecting any collisions of our bubble with ambient defects is greatly enhanced in the case where the cosmological constant of our parent vacuum is much higher than the vacuum energy density during inflation in our bubble.

  15. Background sources and masks for Mark II detector at PEP

    SciTech Connect (OSTI)

    Kadyk, J.

    1981-06-01T23:59:59.000Z

    The shielding masks currently at use in several of the current experiments at PEP are the result of an early organized effort to understand the sources of particle background expected at PEP, followed by the evolution of the conceptual designs into actual hardware. The degree and kind of background particle loading which could be tolerated was expected to differ significantly among the different experiments, and several designs emerged from the common study. Qualitatively, the types of radiations studied were, Synchrotron Radiation (SR), Beam Gas Bremsstrahlung (BGB), and, to a limited extent others, e.g., Electroproduction (EP). Calculations will be given of predicted occupancies in the pipe counter and other sensitive elements at small radius, since these will be most susceptible to the SR and BGB backgrounds. The calculations presented in this note are specific to the Mark II detector. Some general statements will be made first about the character of each of the various types of backgrounds considered, then some detailed calculations made for application to the Mark II detector.

  16. Proceedings of NAMRI/SME, Vol. 40, 2012 Smooth Surface Fabrication in Mask Projection based

    E-Print Network [OSTI]

    Chen, Yong

    Proceedings of NAMRI/SME, Vol. 40, 2012 Smooth Surface Fabrication in Mask Projection based-stepping effect. #12;Proceedings of NAMRI/SME, Vol. 40, 2012 In this paper, we present an alternative approach

  17. Defect CFTs and holographic multiverse

    E-Print Network [OSTI]

    Bartomeu Fiol

    2010-04-09T23:59:59.000Z

    We investigate some aspects of a recent proposal for a holographic description of the multiverse. Specifically, we focus on the implications on the suggested duality of the fluctuations of a bubble separating two universes with different cosmological constants. We do so by considering a similar problem in a 2+1 CFT with a codimension one defect, obtained by an M5-brane probe embedding in AdS_4x S^7, and studying its spectrum of fluctuations. Our results suggest that the kind of behavior required by the spectrum of bubble fluctuations is not likely to take place in defect CFTs with an AdS dual, although it might be possible if the defect supports a non-unitary theory.

  18. Defect CFTs and holographic multiverse

    SciTech Connect (OSTI)

    Fiol, Bartomeu, E-mail: bfiol@ub.edu [Departament de Física Fonamental i Institut de Cičncies del Cosmos, Universitat de Barcelona, Martí i Franqučs 1, 08193 Barcelona (Spain)

    2010-07-01T23:59:59.000Z

    We investigate some aspects of a recent proposal for a holographic description of the multiverse. Specifically, we focus on the implications on the suggested duality of the fluctuations of a bubble separating two universes with different cosmological constants. We do so by considering a similar problem in a 2+1 CFT with a codimension one defect, obtained by an M5-brane probe embedding in AdS{sub 4} × S{sup 7}, and studying its spectrum of fluctuations. Our results suggest that the kind of behavior required by the spectrum of bubble fluctuations is not likely to take place in defect CFTs with an AdS dual, although it might be possible if the defect supports a non-unitary theory.

  19. Integrated circuit mask generation using a raster scanned laser trimming system

    E-Print Network [OSTI]

    Gourley, Kevin Dwayne

    1982-01-01T23:59:59.000Z

    INTEGRATED CIRCUIT MASK GENERATION USING A RASTER SCANNED LASER TRIMMING SYSTEM A Thesis by KEVIN DWAYNE GOURLEY Submitted to the Graduate College of Texas AA M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1982 Major Subject: Electrical Engineering INTEGRATED CIRCUIT MASK GENERATION USING A RASTER SCANNED LASER TRIMMING SYSTEM A Thesis by KEVIN DWAYNE GOURLEY Approved as to style and content by: hair ma ommittee Dr . Dou as M. Green 4...

  20. An investigation of defect detection using random defect excitation and deterministic defect observation in complex integrated logic circuits

    E-Print Network [OSTI]

    Dworak, Jennifer

    2013-02-22T23:59:59.000Z

    aWhenever integrated circuits are manufactured, a certain percentage of those circuits will be defective. Defective circuits present problems for both the manufacturers who wish to maintain a good reputation with their customers and the consumers...

  1. MESOSCALE DESCRIPTION OF DEFECTED MATERIALS

    E-Print Network [OSTI]

    Vinals, Jorge

    MESOSCALE DESCRIPTION OF DEFECTED MATERIALS Jorge Vi~nals School of Physics and Astronomy. Laughlin) Small but finite wavenumber and finite frequency ("mesoscale") response functions and transport;MESOSCALE DESCRIPTION B B B B B B B A B A B A A B B A A A A BB A B Microscopic Mesoscopic Macroscopic vn

  2. Random laser from engineered nanostructures obtained by surface tension driven lithography

    E-Print Network [OSTI]

    Ghofraniha, N; Di Maria, F; Barbarella, G; Gigli, G; Conti, C

    2013-01-01T23:59:59.000Z

    The random laser emission from the functionalized thienyl-S,S-dioxide quinquethiophene (T5OCx) in confined patterns with different shapes is demonstrated. Functional patterning of the light emitter organic material in well defined features is obtained by spontaneous molecular self-assembly guided by surface tension driven (STD) lithography. Such controlled supramolecular nano-aggregates act as scattering centers allowing the fabrication of one-component organic lasers with no external resonator and with desired shape and efficiency. Atomic force microscopy shows that different geometric pattern with different supramolecular organization obtained by the lithographic process tailors the coherent emission properties by controlling the distribution and the size of the random scatterers.

  3. Wafer chamber having a gas curtain for extreme-UV lithography

    DOE Patents [OSTI]

    Kanouff, Michael P. (Livermore, CA); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2001-01-01T23:59:59.000Z

    An EUVL device includes a wafer chamber that is separated from the upstream optics by a barrier having an aperture that is permeable to the inert gas. Maintaining an inert gas curtain in the proximity of a wafer positioned in a chamber of an extreme ultraviolet lithography device can effectively prevent contaminants from reaching the optics in an extreme ultraviolet photolithography device even though solid window filters are not employed between the source of reflected radiation, e.g., the camera, and the wafer. The inert gas removes the contaminants by entrainment.

  4. Diffraction spectral filter for use in extreme-UV lithography condenser

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Tichenor, Daniel A. (Castro Valley, CA); Bernardez, Luis J. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    A condenser system for generating a beam of radiation includes a source of radiation light that generates a continuous spectrum of radiation light; a condenser comprising one or more first optical elements for collecting radiation from the source of radiation light and for generating a beam of radiation; and a diffractive spectral filter for separating first radiation light having a particular wavelength from the continuous spectrum of radiation light. Cooling devices can be employed to remove heat generated. The condenser system can be used with a ringfield camera in projection lithography.

  5. Photonic assisted light trapping integrated in ultrathin crystalline silicon solar cells by nanoimprint lithography

    E-Print Network [OSTI]

    Trompoukis, Christos; Depauw, Valérie; Gordon, Ivan; Poortmans, Jef; 10.1063/1.4749810.

    2012-01-01T23:59:59.000Z

    We report on the fabrication of two-dimensional periodic photonic nanostructures by nanoimprint lithography and dry etching, and their integration into a 1-{\\mu}m-thin mono-crystalline silicon solar cell. Thanks to the periodic nanopatterning, a better in-coupling and trapping of light is achieved, resulting in an absorption enhancement. The proposed light trapping mechanism can be explained as the superposition of a graded index effect and of the diffraction of light inside the photoactive layer. The absorption enhancement is translated into a 23% increase in short-circuit current, as compared to the benchmark cell, resulting in an increase in energy-conversion efficiency.

  6. Anticorrelation between Surface and Subsurface Point Defects...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    between Surface and Subsurface Point Defects and the Impact on the Redox Chemistry of TiO2(110). Anticorrelation between Surface and Subsurface Point Defects and the...

  7. Ultra-lightweight nanorelief networks : photopatterned microframes

    E-Print Network [OSTI]

    Choi, Taeyi

    2007-01-01T23:59:59.000Z

    Lightweight nano-network structures in polymers have been fabricated and investigated for their mechanical properties. Fabrication techniques via holographic interference lithography and phase mask lithography were implemented ...

  8. Learning Defect Predictors:Lessons from the Trenches Learning Defect Predictors

    E-Print Network [OSTI]

    Menzies, Tim

    Learning Defect Predictors:Lessons from the Trenches Learning Defect Predictors: Lessons from the Trenches Tim Menzies LCSEE, WVU tim@menzies.us October 28, 2008 1 / 40 #12;Learning Defect Predictors:Lessons change the rules of the game. 2 / 40 #12;Learning Defect Predictors:Lessons from the Trenches

  9. Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction

    SciTech Connect (OSTI)

    Park, Joong-Mok; Gan, Zhengqing; Leung, Wai Y.; Liu, Rui; Ye, Zhuo; Constant, Kristen; Shinar, Joseph; Shinar, Ruth; Ho, Kai-Ming

    2011-06-06T23:59:59.000Z

    Very uniform 2 {micro}m-pitch square microlens arrays ({micro}LAs), embossed on the blank glass side of an indium-tin-oxide (ITO)-coated 1.1 mm-thick glass, are used to enhance light extraction from organic light-emitting diodes (OLEDs) by {approx}100%, significantly higher than enhancements reported previously. The array design and size relative to the OLED pixel size appear to be responsible for this enhancement. The arrays are fabricated by very economical soft lithography imprinting of a polydimethylsiloxane (PDMS) mold (itself obtained from a Ni master stamp that is generated from holographic interference lithography of a photoresist) on a UV-curable polyurethane drop placed on the glass. Green and blue OLEDs are then fabricated on the ITO to complete the device. When the {mu}LA is {approx}15 x 15 mm{sup 2}, i.e., much larger than the {approx}3 x 3 mm{sup 2} OLED pixel, the electroluminescence (EL) in the forward direction is enhanced by {approx}100%. Similarly, a 19 x 25 mm{sup 2} {mu}LA enhances the EL extracted from a 3 x 3 array of 2 x 2 mm{sup 2} OLED pixels by 96%. Simulations that include the effects of absorption in the organic and ITO layers are in accordance with the experimental results and indicate that a thinner 0.7 mm thick glass would yield a {approx}140% enhancement.

  10. Extending ion-track lithography to the low-energy ion regime

    SciTech Connect (OSTI)

    Musket, R.G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2006-06-01T23:59:59.000Z

    Ion tracking and ion-track lithography have been performed almost exclusively using ions with energies near or above the maximum in electronic stopping, which occurs at {approx}1 MeV/amu. In this paper, ion-track lithography using ions with energies well below this maximum is discussed. The results of etching ion tracks created in polycarbonate films by ions with energies just above the anticipated threshold for creating etchable latent tracks with cylindrical geometry have been examined. Low-energy neon and argon ions with 18-60 keV/amu and fluences of {approx}10{sup 8} cm{sup -2} were used to examine the limits for producing useful, etchable tracks in polycarbonate films. By concentrating on the early stages of etching (i.e., {approx}20 nm

  11. Extending ion-track lithography to the low-energy ion regime

    SciTech Connect (OSTI)

    Musket, R G

    2005-10-14T23:59:59.000Z

    Ion tracking and ion-track lithography have been performed almost exclusively using ions with energies near or above the maximum in electronic stopping, which occurs at {approx}1 MeV/amu. In this paper, ion-track lithography using ions with energies well below this maximum is discussed. The results of etching ion tracks created in polycarbonate films by ions with energies just above the anticipated threshold for creating etchable latent tracks with cylindrical geometry have been examined. Low-energy neon and argon ions with 18-60 keV/amu and fluences of {approx}10{sup 8}/cm{sup 2} were used to examine the limits for producing useful, etchable tracks in polycarbonate films. By concentrating on the early stages of etching (i.e., {approx}20 nm < SEM hole diameter < {approx}100 nm), the energy deposition calculated for the incident ion was correlated with the creation of etchable tracks. The experimental results are discussed with regard to the energy losses of the ions in the polycarbonate films and to the formation of continuous latent tracks through the entire thickness of the films. The probability distributions for large-angle scattering events were calculated to assess their importance as a function of ion energy. All these results have significant implications with respect to the threshold for formation of etchable tracks and to the use of low-energy ions for lithographic applications of ion tracking.

  12. Evaluation of Setup Uncertainties for Single-Fraction SRS by Comparing the Two Different Mask-Creation Methods

    E-Print Network [OSTI]

    Baek, Jong Geun; Oh, Young Kee; Lee, Hyun Jeong; Kim, Eng Chan

    2015-01-01T23:59:59.000Z

    The purpose of this study was to evaluate the setup uncertainties for single-fraction stereotactic radiosurgery (SF-SRS) based on the clinical data with the two different mask-creation methods using pretreatment CBCT imaging guidance. Dedicated frameless fixation BrainLAB masks for 23 patients were created as a routine mask (R-mask) making method, as explained in the BrainLAB user manual. The alternative masks (A-mask) which were created by modifying the cover range of the R-mask for the patient head were used for 23 patients. The systematic errors including the each mask and stereotactic target localizer were analyzed and the errors were calculated as the mean and standard deviation (SD) from the LR, SI, AP, and yaw setup corrections. In addition, the frequency of three-dimensional (3D) vector length were also analyzed. The values of the mean setup corrections for the R-mask in all directions were small; < 0.7 mm and < 0.1 degree, whereas the magnitudes of the SDs were relatively large compared to the ...

  13. Atomic Scale Details of Defect-Boundary Interactions

    E-Print Network [OSTI]

    Chen, Di

    2014-12-18T23:59:59.000Z

    consists of alternately positioned interstitials and vacancies. The subsequent defect annihilation between neighboring defects on the chain leads to the defect transport. We identify three types of defect transport models which involve different chains...

  14. Gravitational energy of conical defects

    E-Print Network [OSTI]

    J. W. Maluf; A. Kneip

    1996-08-22T23:59:59.000Z

    The energy density of asymptotically flat gravitational fields can be calculated from a simple expression involving the trace of the torsion tensor. Integration of this energy density over the whole space yields the ADM energy. Such expression can be justified within the framework of the teleparallel equivalent of general relativity, which is an alternative geometrical formulation of Einstein's general relativity. In this paper we apply this energy density to the evaluation of the energy per unit length of a class of conical defects of topological nature, which include disclinations and dislocations (in the terminology of crystallography). Disclinations correspond to cosmic strings, and for a spacetime endowed with only such a defect we obtain precisely the well known expression of energy per unit length. However for a pure spacetime dislocation the total gravitational energy is zero.

  15. PATENT/DISCLOSURE LIST (1) A. Bindal, "Sidewall Lithography for Growing Horizontal Carbon Nano Tubes and a

    E-Print Network [OSTI]

    Eirinaki, Magdalini

    Tubes and a Process Flow for Complementary Carbon Nano Tube Field Effect Transistor (CCFET) FabricationPATENT/DISCLOSURE LIST (1) A. Bindal, "Sidewall Lithography for Growing Horizontal Carbon Nano for Manufacturing Nano-Interconnects and Catalyst Islands for Growing Carbon Nano Tubes", provisional patent

  16. Polymer sphere lithography for solid oxide fuel cells: a route to functional, well-defined electrode structures

    E-Print Network [OSTI]

    Polymer sphere lithography for solid oxide fuel cells: a route to functional, well. Introduction Dramatic breakthroughs in the materials, particularly electrode materials, for solid oxide fuel cells (SOFCs) have been reported in recent years.1­3 Fundamental understanding of the electro- catalytic

  17. Scanning probe lithography of self-assembled monolayers Guohua Yang, Nabil A. Amro, Gang-yu Liu*

    E-Print Network [OSTI]

    Liu, Gang-yu

    Scanning probe lithography of self-assembled monolayers Guohua Yang, Nabil A. Amro, Gang-yu Liu* Department ofChemistry, University ofCalifornia, Davis, CA, USA 95616 ABSTRACT Systematic studies on scanning, and nanopen reader and writer (NPRW), which rely on the local force, and two scanning tunneling microscopy

  18. Fabrication of planar quantum magnetic disk structure using electron beam lithography, reactive ion etching, and chemical mechanical polishing

    E-Print Network [OSTI]

    Fabrication of planar quantum magnetic disk structure using electron beam lithography, reactive ion, Department of Electrical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 Received 2 June's size and location, and reactive ion etching was used to form an SiO2 template. Nickel electroplating

  19. Conformal nets III: fusion of defects

    E-Print Network [OSTI]

    Arthur Bartels; Christopher L. Douglas; André Henriques

    2015-02-21T23:59:59.000Z

    Conformal nets provides a mathematical model for conformal field theory. We define a notion of defect between conformal nets, formalizing the idea of an interaction between two conformal field theories. We introduce an operation of fusion of defects, and prove that the fusion of two defects is again a defect, provided the fusion occurs over a conformal net of finite index. There is a notion of sector (or bimodule) between two defects, and operations of horizontal and vertical fusion of such sectors. Our most difficult technical result is that the horizontal fusion of the vacuum sectors of two defects is isomorphic to the vacuum sector of the fused defect. Equipped with this isomorphism, we construct the basic interchange isomorphism between the horizontal fusion of two vertical fusions and the vertical fusion of two horizontal fusions of sectors.

  20. A novel approach to reconstructing signals of isotropy violation from a masked CMB sky

    E-Print Network [OSTI]

    Aluri, Pavan K; Rotti, Aditya; Souradeep, Tarun

    2015-01-01T23:59:59.000Z

    Statistical isotropy (SI) is one of the fundamental assumptions made in cosmological model building. This assumption is now being rigorously tested using the almost full sky measurements of the CMB anisotropies. A major hurdle in any such analysis is to handle the large biases induced due to the process of masking. We have developed a new method of analysis, using the bipolar spherical harmonic basis functions, in which we semi-analytically evaluate the modifications to SI violation induced by the mask. The method developed here is generic and can be potentially used to search for any arbitrary form of SI violation. We specifically demonstrate the working of this method by recovering the Doppler boost signal from a set of simulated, masked CMB skies.

  1. Use of a hard mask for formation of gate and dielectric via nanofilament field emission devices

    DOE Patents [OSTI]

    Morse, Jeffrey D. (Martinez, CA); Contolini, Robert J. (Lake Oswego, OR)

    2001-01-01T23:59:59.000Z

    A process for fabricating a nanofilament field emission device in which a via in a dielectric layer is self-aligned to gate metal via structure located on top of the dielectric layer. By the use of a hard mask layer located on top of the gate metal layer, inert to the etch chemistry for the gate metal layer, and in which a via is formed by the pattern from etched nuclear tracks in a trackable material, a via is formed by the hard mask will eliminate any erosion of the gate metal layer during the dielectric via etch. Also, the hard mask layer will protect the gate metal layer while the gate structure is etched back from the edge of the dielectric via, if such is desired. This method provides more tolerance for the electroplating of a nanofilament in the dielectric via and sharpening of the nanofilament.

  2. Dry Lithography of Large-Area, Thin-Film Organic Semiconductors Using Frozen CO[subscript 2] Resists

    E-Print Network [OSTI]

    Mendoza, Hiroshi A.

    To address the incompatibility of organic semiconductors with traditional photolithography, an inert, frozen CO[subscript 2] resist is demonstrated that forms an in situ shadow mask. Contact with a room-temperature ...

  3. A NOVEL APPROACH TO SOFT-MASK ESTIMATION AND LOG-SPECTRAL ENHANCEMENT FOR ROBUST SPEECH RECOGNITION

    E-Print Network [OSTI]

    Alwan, Abeer

    A NOVEL APPROACH TO SOFT-MASK ESTIMATION AND LOG-SPECTRAL ENHANCEMENT FOR ROBUST SPEECH RECOGNITION-- Speech Recognition, Feature Extraction, Speech Enhancement, Mask Estimation, Median Filtering. 1 enhancement. Reliable SPPs provide clues about the spectro-temporal location of speech and are thus a highly

  4. Failure of signed chromatic apparent motion with luminance masking Tatsuya Yoshizawa, Kathy T. Mullen, Curtis L. Baker Jr. *

    E-Print Network [OSTI]

    Mullen, Kathy T.

    Failure of signed chromatic apparent motion with luminance masking Tatsuya Yoshizawa, Kathy T measured in the presence of a dynamic luminance masking noise. Increasing the luminance noise contrast­green chromatic motion is derived from a luminance- based signal, rather than a genuinely chromatic motion

  5. Evolution of Topological Defects During Inflation

    E-Print Network [OSTI]

    R. Basu; A. Vilenkin

    1994-02-22T23:59:59.000Z

    Topological defects can be formed during inflation by phase transitions as well as by quantum nucleation. We study the effect of the expansion of the Universe on the internal structure of the defects. We look for stationary solutions to the field equations, i.e. solutions that depend only on the proper distance from the defect core. In the case of very thin defects, whose core dimensions are much smaller than the de Sitter horizon, we find that the solutions are well approximated by the flat space solutions. However, as the flat space thickness parameter $\\delta_0$ increases we notice a deviation from this, an effect that becomes dramatic as $\\delta_0$ approaches $(H)^{-1}/{\\sqrt 2}$. Beyond this critical value we find no stationary solutions to the field equations. We conclude that only defects that have flat space thicknesses less than the critical value survive, while thicker defects are smeared out by the expansion.

  6. Space-time defects and teleparallelism

    E-Print Network [OSTI]

    J. W. Maluf; A. Goya

    2001-10-24T23:59:59.000Z

    We consider the class of space-time defects investigated by Puntigam and Soleng. These defects describe space-time dislocations and disclinations (cosmic strings), and are in close correspondence to the actual defects that arise in crystals and metals. It is known that in such materials dislocations and disclinations require a small and large amount of energy, respectively, to be created. The present analysis is carried out in the context of the teleparallel equivalent of general relativity (TEGR). We evaluate the gravitational energy of these space-time defects in the framework of the TEGR and find that there is an analogy between defects in space-time and in continuum material systems: the total gravitational energy of space-time dislocations and disclinations (considered as idealized defects) is zero and infinit, respectively.

  7. A direct-write thick-film lithography process for multi-parameter control of tooling in continuous roll-to-roll microcontact printing

    E-Print Network [OSTI]

    Nietner, Larissa F

    2014-01-01T23:59:59.000Z

    Roll-to-roll (R2R) microcontact printing ([mu]CP) aims to transform micron-precision soft lithography in a continuous, large-scale, high-throughput process for large-area surface patterning, flexible electronics and ...

  8. Effect of carbon contamination on the printing performance of extreme ultraviolet masks

    E-Print Network [OSTI]

    Effect of carbon contamination on the printing performance of extreme ultraviolet masks Yu-Jen Fan November 2009; accepted 2 February 2010; published 22 March 2010 Carbon contamination is a significant on imaging performance. Current carbon contamination research is primarily focused on the lifetime

  9. Carbon Contamination of Extreme Ultraviolet (EUV) Masks and its Effect on Imaging

    E-Print Network [OSTI]

    Carbon Contamination of Extreme Ultraviolet (EUV) Masks and its Effect on Imaging Yu-Jen Fan1 3. CXRO, Lawrence Berkeley National Laboratory, Berkeley CA ABSTRACT Carbon contamination of extreme and potential effects on imaging performance. In this work, a series of carbon contamination experiments were

  10. The application of nanosecond-pulsed laser welding technology in MEMS packaging with a shadow mask$

    E-Print Network [OSTI]

    Lin, Liwei

    The application of nanosecond-pulsed laser welding technology in MEMS packaging with a shadow mask wiring is not pre- ferred. A comprehensive review on laser welding was given in [6]. The laser welding of laser welding is to create the liquid pool by absorption of incident radiation, allow it to grow

  11. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOE Patents [OSTI]

    Hubbell, Earl A. (Mt. View, CA); Lipshutz, Robert J. (Palo Alto, CA); Morris, Macdonald S. (San Jose, CA); Winkler, James L. (Palo Alto, CA)

    1997-01-01T23:59:59.000Z

    An improved set of computer tools for forming arrays. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks.

  12. Mask estimation for missing data speech recognition based on statistics of binaural interaction

    E-Print Network [OSTI]

    Barker, Jon

    1 Mask estimation for missing data speech recognition based on statistics of binaural interaction to a target sound source in the presence of other This work was funded by EPSRC grant GR/R47400 comparisons are used to cancel interfering sound sources [5] or actively group acoustic energy which

  13. Multi-Color Coronagraph Experiment in a Vacuum Testbed with a Binary Shaped Pupil Mask

    E-Print Network [OSTI]

    Haze, Kanae; Abe, Lyu; Kotani, Takayuki; Nakagawa, Takao; Sato, Toshimichi; Yamamuro, Tomoyasu

    2011-01-01T23:59:59.000Z

    We conducted a number of multi-band coronagraph experiments using a vacuum chamber and a binary-shaped pupil mask which in principle should work at all wavelengths, in the context of the research and development on a coronagraph to observe extra-solar planets (exoplanets) directly. The aim of this work is to demonstrate that subtraction of Point Spread Function (PSF) and multi-band experiments using a binary-shaped pupil mask coronagraph would help improve the contrast in the observation of exoplanets. A checkerboard mask, a kind of binary-shaped pupil mask, was used. We improved the temperature stability by installing the coronagraph optics in a vacuum chamber, controlling the temperature of the optical bench, and covering the vacuum chamber with thermal insulation layers. We evaluated how much the PSF subtraction contributes to the high contrast observation by subtracting the images obtained through the coronagraph. We also carried out multi- band experiments in order to demonstrate a more realistic observa...

  14. Analysis of a Mask-Based Nanowire Decoder Eric Rachlin, John E. Savage and Benjamin Gojman

    E-Print Network [OSTI]

    DeHon, André

    a moderate number of mesoscale wires. Three methods have been proposed to use mesoscale wires to control random doped connections between nanowires and mesoscale wires, and the third, a mask-based approach, in- terposes high-K dielectric regions between nanowires and mesoscale wires. All three addressing schemes

  15. Track-etched nanopores in spin-coated polycarbonate films applied as sputtering mask

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 2 - Track-etched nanopores in spin-coated polycarbonate films applied as sputtering mask A Schwerionenforschung (GSI), Darmstadt, Germany 4 Hahn-Meitner-Institut, Berlin, Germany Abstract Thin polycarbonate.80.Jh; 61.82Pv Keywords: polycarbonate, ion track, etching, sputtering, swift heavy ion irradiation #12

  16. Genetic refinement of cloud-masking algorithms for the multi-spectral thermal imager (MTI)

    SciTech Connect (OSTI)

    Hirsch, K. L. (Karen L.); Davis, A. B. (Anthony B.); Harvey, N. R. (Neal R.); Rohde, C. A. (Charles A.); Brumby, Steven P.

    2001-01-01T23:59:59.000Z

    The Multi-spectral Thermal Imager (MTI) is a high-performance remote-sensing satellite designed, owned and operated by the U.S. Department of Energy, with a dual mission in environmental studies and in nonproliferation. It has enhanced spatial and radiometric resolutions and state-of-the-art calibration capabilities. This instrumental development puts a new burden on retrieval algorithm developers to pass this accuracy on to the inferred geophysical parameters. In particular, the atmospheric correction scheme assumes the intervening atmosphere will be modeled as a plane-parallel horizontally-homogeneous medium. A single dense-enough cloud in view of the ground target can easily offset reality from the calculations, hence the need for a reliable cloud-masking algorithm. Pixel-scale cloud detection relies on the simple facts that clouds are generally whiter, brighter, and colder than the ground below; spatially, dense clouds are generally large on some scale. This is a good basis for searching multispectral datacubes for cloud signatures. However, the resulting cloud mask can be very sensitive to the choice of thresholds in whiteness, brightness, temperature, and connectivity. We have used a genetic algorithm trained on (MODIS Airborne Simulator-based) simulated MTI data to design a cloud-mask. Its performance is compared quantitatively to hand-drawn training data and to the EOS/Terra MODIS cloud mask.

  17. Model Selection for the Competing-Risks Model With and Without Masking

    E-Print Network [OSTI]

    Lee, Chun Man "Thomas"

    Department of Statistics Colorado State University Fort Collins, CO 80523-1877 (tlee@stat.colostate.edu) The competing-risks model is useful in settings in which individuals (or units) may die (or fail) because for competing-risks data with and without masking involves the specification of cause-specific hazard rates

  18. SINGLE-MASK, HIGH ASPECT RATIO, 3-D MICROMACHINING OF BULK TITANIUM , M. F. Aimi2

    E-Print Network [OSTI]

    MacDonald, Noel C.

    SINGLE-MASK, HIGH ASPECT RATIO, 3-D MICROMACHINING OF BULK TITANIUM M. P. Rao1 , M. F. Aimi2 , E. R profiles in bulk titanium. The method relies on the exploitation of Reactive Ion Etching Lag (RIE Lag for application in bulk micromachined titanium micromirror devices. 1. INTRODUCTION The recent development

  19. Giving and Thanksgiving: Gratitude and Adiaphora in A Mask and Paradise Regained

    E-Print Network [OSTI]

    Newberry, Julie Nicole

    2011-10-21T23:59:59.000Z

    in Paradise Lost, but scholars have not fully appreciated the role of this virtue elsewhere in Milton's writing. This thesis is an attempt to redress that oversight with reference to A Mask and Paradise Regained, while also answering a question that Medine...

  20. Comparison of sequence masking algorithms and the detection of biased protein sequence

    E-Print Network [OSTI]

    Kreil, David

    Comparison of sequence masking algorithms and the detection of biased protein sequence regions;Abstract Motivation Separation of protein sequence regions according to their local information complexity by sequence similarity. Comparison with alternative methods that focus on compositional sequence bias rather

  1. Can we stop the spread of influenza in schools with face masks?

    SciTech Connect (OSTI)

    Del Valle, Sara Y [Los Alamos National Laboratory; Tellier, Raymond [UNIV OF CALGARY; Settles, Gary [UNIV PARK; Tang, Julian [NATIONAL UNIV OF SINGAPORE

    2009-01-01T23:59:59.000Z

    In the absence of a strain-specific vaccine and the potential resistance to antiviral medication, nonpharmaceutical interventions can be used to reduce the spread of an infectious disease such as influenza. The most common non-pharmaceutical interventions include school closures, travel restrictions, social distancing, enforced or volunteer home isolation and quarantine, improved hand hygiene, and the appropriate wearing of face masks. However, for some of these interventions, there are some unavoidable economic costs to both employees and employers, as well as possible additional detriment to society as a whole. For example, it has been shown that school-age children are most likely to be infected and act as sources of infection for others, due to their greater societal interaction and increased susceptibility. Therefore, preventing or at least reducing infections in children is a logical first-line of defense. For this reason, school closures have been widely investigated and recommended as part of pandemic influenza preparedness, and some studies support this conclusion. Yet, school closures would result in lost work days if at least one parent must be absent from work to care for children who would otherwise be at school. In addition, the delay in-academic progress may be detrimental due to mass school absenteeism. In particular, the pandemic influenza guidance by the U.S. Department of Health and Human Services recommends school closures for less than four weeks for Category 2 and 3 pandemics (i.e., similar to the milder 1957 and 1968 pandemics) and one to three months for Category 4 and 5 pandemics (i .e., similar to the 1918 pandemic ). Yet, given the above, it is clear that closing schools for up to three months is unlikely to be a practical mitigation strategy for many families and society. Thus modelers and policy makers need to weigh all factors before recommending such drastic measures, particularly if the agent under consideration typically has low mortality and causes a mild disease. Therefore, we contend that face masks are an effective, practical, non-pharmaceutical intervention that would reduce the spread of disease among school-children, while keeping schools open. Influenza spreads through person-to-person contact, via transmission by large droplets or aerosols (droplet nuclei) produced by breathing, talking, coughing or sneezing, as well as by direct (though most people touch very few others in their daily lives) or indirect (i.e., via fomites) contact. Face masks act as a physical barrier to reduce the amount of potentially infectious inhaled and exhaled particles, although they would not reliably protect the wearer against aerosols; a recent study also demonstrated that they can redirect and decelerate exhaled airflows (when worn by an infected individual) to prevent them from entering the breathing zones of others. Thus, if a whole classroom were to don face masks, disease transmission would be expected to be greatly diminished. Another recent study on face masks and hand hygiene show a 10-50% transmission reduction for influenza-like illnesses. Furthermore, face masks can act as an effective physical reminder and barrier to transmission by preventing the wearer from touching any potentially infectious secretions from their mucous membranes (i.e., from the nose and mouth), which is another mechanism for direct and indirect contact transmission for influenza. A recent systematic review has suggested that wearing masks can be highly effective in limiting the transmission of respiratory infections, such as influenza. Yet, admittedly, the effectiveness of this intervention strategy is highly dependent on compliance (i.e., the willingness to wear the mask in all appropriate situations), which in tum depends on comfort, convenience, fitness, and hygiene. Importantly, masks themselves must not become a source of infection (or reinfection); as such they should be replaced or sanitized daily (where possible) to maximize effectiveness. One solution could be for masks to be touted as fashion accessories, whi

  2. System and methods for determining masking signals for applying empirical mode decomposition (EMD) and for demodulating intrinsic mode functions obtained from application of EMD

    DOE Patents [OSTI]

    Senroy, Nilanjan (New Delhi, IN); Suryanarayanan, Siddharth (Littleton, CO)

    2011-03-15T23:59:59.000Z

    A computer-implemented method of signal processing is provided. The method includes generating one or more masking signals based upon a computed Fourier transform of a received signal. The method further includes determining one or more intrinsic mode functions (IMFs) of the received signal by performing a masking-signal-based empirical mode decomposition (EMD) using the at least one masking signal.

  3. Defect Analysis of Vehicle Compressed Natural Gas

    E-Print Network [OSTI]

    Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder A China Paper on Type 4;Industrial Computed Tomography (CT) Examination of Composite Gas Cylinder #12;CT of 01-01 Layer at 4.8MPa during the gas compressing and releasing processes are the direct causes for liner defect - Since

  4. DefectDomain Wall Interactions in Trigonal

    E-Print Network [OSTI]

    Gopalan, Venkatraman

    Defect­Domain Wall Interactions in Trigonal Ferroelectrics Venkatraman Gopalan,1 Volkmar Dierolf,2 walls in the trigonal ferroelectrics lithium niobate and lithium tantalate. It is shown that extrinsic questions re- garding intrinsic widths, defect­domain wall interactions, and static versus dynamic wall

  5. Predicting software defects in varying development lifecycles

    E-Print Network [OSTI]

    Bae, Doo-Hwan

    Predicting software defects in varying development lifecycles using Bayesian nets Information and Software Technology (2007) Norman Fenton, Martin Neil, William March, Peter HyeonJeong Kim KAIST SE LAB #12;Contents Introduction Overall approach Analyzing the lifecycle Modeling the defect prediction

  6. First-principles study of the structural, electronic, and optical properties of Ga2O3 in its monoclinic and hexagonal phases

    E-Print Network [OSTI]

    Pandey, Ravi

    electrodes for flat panel displays and solar cells, and phase shift masks for laser lithography. Ga2O3 has

  7. Coulomb screening in graphene with topological defects

    E-Print Network [OSTI]

    Baishali Chakraborty; Kumar S. Gupta; Siddhartha Sen

    2015-02-20T23:59:59.000Z

    We analyze the screening of an external Coulomb charge in gapless graphene cone, which is taken as a prototype of a topological defect. In the subcritical regime, the induced charge is calculated using both the Green's function and the Friedel sum rule. The dependence of the polarization charge on the Coulomb strength obtained from the Green's function clearly shows the effect of the conical defect and indicates that the critical charge itself depends on the sample topology. Similar analysis using the Friedel sum rule indicates that the two results agree for low values of the Coulomb charge but differ for the higher strengths, especially in the presence of the conical defect. For a given subcritical charge, the transport cross-section has a higher value in the presence of the conical defect. In the supercritical regime we show that the coefficient of the power law tail of polarization charge density can be expressed as a summation of functions which vary log periodically with the distance from the Coulomb impurity. The period of variation depends on the conical defect. In the presence of the conical defect, the Fano resonances begin to appear in the transport cross-section for a lower value of the Coulomb charge. For both sub and supercritical regime we derive the dependence of LDOS on the conical defect. The effects of generalized boundary condition on the physical observables are also discussed.

  8. Modeling defective part level due to static and dynamic defects based upon site observation and excitation balance

    E-Print Network [OSTI]

    Dworak, Jennifer Lynn

    2004-09-30T23:59:59.000Z

    defect detection. We deterministically maximize the observations of the leastobserved sites while randomly exciting the defects that may be present. The resulting decrease in defective part level is estimated using the MPGD model. This dissertation...

  9. Defect classes - an overdue paradigm for CMOS IC testing

    SciTech Connect (OSTI)

    Hawkins, C.F. [Univ. of New Mexico, Albuquerque, NM (United States); Soden, J.M.; Righter, A.W. [Sandia National Labs., Albuquerque, NM (United States); Ferguson, F.J. [Univ. of California, Santa Cruz, CA (United States)

    1994-09-01T23:59:59.000Z

    The IC test industry has struggled for more than 30 years to establish a test approach that would guarantee a low defect level to the customer. We propose a comprehensive strategy for testing CMOS ICs that uses defect classes based on measured defect electrical properties. Defect classes differ from traditional fault models. Our defect class approach requires that the test strategy match the defect electrical properties, while fault models require that IC defects match the fault definition. We use data from Sandia Labs failure analysis and test facilities and from public literature. We describe test pattern requirements for each defect class and propose a test paradigm.

  10. Defect Distribution and Dissolution Morphologies on Low-Index...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Defect Distribution and Dissolution Morphologies on Low-Index Surfaces of alpha-Quartz . Defect Distribution and Dissolution Morphologies on Low-Index Surfaces of alpha-Quartz ....

  11. Energetics of Defects on Graphene through Fluorination. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Defects on Graphene through Fluorination. Energetics of Defects on Graphene through Fluorination. Abstract: In the present study, we used FGS5 as the substrate and implemented...

  12. Exploring the interaction between lithium ion and defective graphene...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Exploring the interaction between lithium ion and defective graphene surface using dispersion corrected DFT studies. Exploring the interaction between lithium ion and defective...

  13. Modification of Defect Structures in Graphene by Electron Irradiation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations. Modification of Defect Structures in Graphene by Electron...

  14. Role of Point Defects on the Reactivity of Reconstructed Anatase...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Point Defects on the Reactivity of Reconstructed Anatase Titanium Dioxide (001) Surface. Role of Point Defects on the Reactivity of Reconstructed Anatase Titanium Dioxide (001)...

  15. New Educational Software for Teaching the Sunpath Diagram and Shading Mask Protractor

    E-Print Network [OSTI]

    Oh, J.; Haberl, J. S.

    .E. Energy Systems Laboratory, Department of Architecture, Texas A&M University, College Station, Texas ABSTRACT The well-known versions of the sunpath diagrams that appear in the AIA's Architectural Graphics Standards are based on the equidistant sky dome... projections and use a shading mask protractor developed by Olgyay and Olgyay at Princeton University in the 1950s. A designer using the AIA's Graphics Standards book, or other printed versions of the sunpath diagram, must select the nearest latitude, make...

  16. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOE Patents [OSTI]

    Hubbell, E.A.; Morris, M.S.; Winkler, J.L.

    1999-01-05T23:59:59.000Z

    An improved set of computer tools for forming arrays is disclosed. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks. 14 figs.

  17. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOE Patents [OSTI]

    Hubbell, E.A.; Lipshutz, R.J.; Morris, M.S.; Winkler, J.L.

    1997-01-14T23:59:59.000Z

    An improved set of computer tools for forming arrays is disclosed. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks. 14 figs.

  18. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOE Patents [OSTI]

    Hubbell, E.A.; Morris, M.S.; Winkler, J.L.

    1996-11-05T23:59:59.000Z

    An improved set of computer tools for forming arrays is disclosed. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks. 14 figs.

  19. ThreeDimensional Metallic Microstructures Fabricated by Soft Lithography and Microelectrodeposition

    E-Print Network [OSTI]

    Whitesides, Sue

    will require new approaches not drawn from existing tech­ nologies. Electroforming (electrodeposition structures by repairing any strain­induced defects with electrodeposition of ad­ ditional metal over bubblememorydevices, 11 thin­ film chip carriers, 2 and components for MEMS (nickel turbine rotor, 5 magnetic

  20. Arrays of nanoscale magnetic dots: Fabrication by x-ray interference lithography and characterization

    SciTech Connect (OSTI)

    Heyderman, L.J.; Solak, H.H.; David, C.; Atkinson, D.; Cowburn, R.P.; Nolting, F. [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Nanomagnetism Group, Department of Physics, University of Durham, Rochester Building, Science Laboratories, South Road, Durham DH1 3LE (United Kingdom); Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2004-11-22T23:59:59.000Z

    X-ray interference lithography (XIL) was employed in combination with electrodeposition to fabricate arrays of nanoscale nickel dots which are uniform over 40 {mu}m and have periods down to 71 nm. Using extreme-ultraviolet light, XIL has the potential to produce magnetic dot arrays over large areas with periods well below 50 nm, and down to a theoretical limit of 6.5 nm for a 13 nm x-ray wavelength. In the nickel dot arrays, we observed the effect of interdot magnetic stray field interactions. Measuring the hysteresis loops using the magneto-optical Kerr effect, a double switching via the vortex state was observed in the nickel dots with diameters down to 44 nm and large dot separations. As the dot separations are reduced to below around 50 nm a single switching, occurring by collective rotation of the magnetic spins, is favored due to interdot magnetic stray field interactions. This results in magnetic flux closure through several dots which could be visualized with micromagnetic simulations. Further evidence of the stray field interactions was seen in photoemission electron microscopy images, where bands of contrast corresponding to chains of coupled dots were observed.

  1. Di-interstitial defect in silicon revisited

    SciTech Connect (OSTI)

    Londos, C. A.; Antonaras, G. [Solid State Section, Physics Department, University of Athens, Panepistimiopolis, Zografos, 157 84 Athens (Greece)] [Solid State Section, Physics Department, University of Athens, Panepistimiopolis, Zografos, 157 84 Athens (Greece); Chroneos, A. [Engineering and Innovation, The Open University, Milton Keynes MK7 6AA (United Kingdom) [Engineering and Innovation, The Open University, Milton Keynes MK7 6AA (United Kingdom); Department of Materials, Imperial College London, London SW7 2BP (United Kingdom)

    2013-11-21T23:59:59.000Z

    Infrared spectroscopy was used to study the defect spectrum of Cz-Si samples following fast neutron irradiation. We mainly focus on the band at 533 cm{sup ?1}, which disappears from the spectra at ?170 °C, exhibiting similar thermal stability with the Si-P6 electron paramagnetic resonance (EPR) spectrum previously correlated with the di-interstitial defect. The suggested structural model of this defect comprises of two self-interstitial atoms located symmetrically around a lattice site Si atom. The band anneals out following a first-order kinetics with an activation energy of 0.88 ± 0.3 eV. This value does not deviate considerably from previously quoted experimental and theoretical values for the di-interstitial defect. The present results indicate that the 533 cm{sup ?1} IR band originates from the same structure as that of the Si-P6 EPR spectrum.

  2. Generalized quantum defect methods in quantum chemistry

    E-Print Network [OSTI]

    Altunata, Serhan

    2006-01-01T23:59:59.000Z

    The reaction matrix of multichannel quantum defect theory, K, gives a complete picture of the electronic structure and the electron - nuclear dynamics for a molecule. The reaction matrix can be used to examine both bound ...

  3. Sandia National Laboratories: Defect-Carrier Interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with SSLS scientist Andy Armstrong using deep level optical spectroscopy to investigate defects in the m-plane GaN. Jim is a professor ... Last Updated: September 6, 2013...

  4. Two-dimensional defects in amorphous materials

    E-Print Network [OSTI]

    Michael Moshe; Eran Sharon; Ido Levin; Hillel Aharoni; Raz Kupferman

    2014-09-09T23:59:59.000Z

    We present a new definition of defects which is based on a Riemannian formulation of incompatible elasticity. Defects are viewed as local deviations of the material's reference metric field, $\\bar{\\mathfrak{g}}$, from a Euclidian metric. This definition allows the description of defects in amorphous materials and the formulation of the elastic problem, using a single field, $\\bar{\\mathfrak{g}}$. We provide a multipole expansion of reference metrics that represent a large family of two-dimensional (2D) localized defects. The case of a dipole, which corresponds to an edge dislocation is studied analytically, experimentally and numerically. The quadrupole term, which is studied analytically, as well as higher multipoles of curvature carry local deformations. These multipoles are good candidates for fundamental strain carrying entities in plasticity theories of amorphous materials and for a continuous modeling of recently developed meta-materials.

  5. Defect analysis using resonant ultrasound spectroscopy 

    E-Print Network [OSTI]

    Flynn, Kevin Joseph

    2009-05-15T23:59:59.000Z

    This thesis demonstrates the practicability of using Resonant Ultrasound Spectroscopy (RUS) in combination with Finite Element Analysis (FEA) to determine the size and location of a defect in a material of known geometry ...

  6. INNOVATIVE EDDY CURRENT PROBE FOR MICRO DEFECTS

    SciTech Connect (OSTI)

    Santos, Telmo G.; Vilaca, Pedro; Quintino, Luisa [IDMEC, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Santos, Jorge dos [GKSS, Max-Planck-Street 1, D-21502 Geesthacht (Germany); Rosado, Luis [IST, UTL, Av. Rovisco Pais, 1049-001 Lisbon (Portugal)

    2010-02-22T23:59:59.000Z

    This paper reports the development of an innovative eddy current (EC) probe, and its application to micro-defects on the root of the Friction Stir Welding (FSW). The new EC probe presents innovative concept issues, allowing 3D induced current in the material, and a lift-off independence. Validation experiments were performed on aluminium alloys processed by FSW. The results clearly show that the new EC probe is able to detect and sizing surface defects about 60 microns depth.

  7. UV nanoimprint lithography for the realization of large-area ordered SiGe/Si(001) island arrays

    SciTech Connect (OSTI)

    Lausecker, E.; Brehm, M.; Grydlik, M.; Hackl, F.; Fromherz, T.; Schaeffler, F.; Bauer, G. [Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, 4040 Linz (Austria); Bergmair, I.; Muehlberger, M. [Functional Surfaces and Nanostructures, Profactor GmbH, 4407 Steyr-Gleink (Austria)

    2011-04-04T23:59:59.000Z

    We use UV nanoimprint lithography for the pit-patterning of silicon substrates. Ordered silicon-germanium islands are grown inside these pits by molecular-beam epitaxy on arrays of 3x3 mm{sup 2} and characterized by atomic force microscopy (AFM) and photoluminescence (PL) measurements. AFM-based statistics reveals an extremely uniform size distribution of the islands in the patterned areas. These results are confirmed by very narrow and uniform PL peaks recorded at various positions across the patterned arrays.

  8. Influence of defects on thermal and mechanical properties of metals

    E-Print Network [OSTI]

    Kamani, Sandeep Kumar

    2009-05-15T23:59:59.000Z

    SDen ..................................... 33 13 Copper with 8 interstitials at 1600K ....................................................... 34 14 Temperature Vs time for copper without defects at 1360K .................... 39 15 Potential energy Vs time for copper without defects... at 1360K .............. 40 16 Total energy Vs time for copper without defects at 1360K .................... 40 17 Average volume Vs temperature for pure copper without defects .......... 41 18 Total energy Vs temperature for copper without defects...

  9. Manufacturing Defects Common to Composite Wind Turbine Blades: Effects of Defects

    E-Print Network [OSTI]

    uni-directional wind turbine fiber-reinforced composite material with an epoxy resin were utilized of wind turbine blades have essentially dictated the use of low cost fiberglass composite materials. Even1 Manufacturing Defects Common to Composite Wind Turbine Blades: Effects of Defects Jared W. Nelson

  10. A topological point defect regulates the evolution of extended defects in irradiated silicon

    E-Print Network [OSTI]

    Wilkins, John

    functional theory calculations establish formation energies, activation barriers, and electronic structures structure. Compared to the experimental gap of 1.16 eV for bulk Si,16 the calculated HSE gap, 1.15 eV, shows interstitial defects in irradiated silicon. Molecular dynamics simulations reveal the role of the bond defect

  11. Wavelet-Smoothed Interpolation of Masked Scientific Data for JPEG 2000 Compression

    SciTech Connect (OSTI)

    Brislawn, Christopher M. [Los Alamos National Laboratory

    2012-08-13T23:59:59.000Z

    How should we manage scientific data with 'holes'? Some applications, like JPEG 2000, expect logically rectangular data, but some sources, like the Parallel Ocean Program (POP), generate data that isn't defined on certain subsets. We refer to grid points that lack well-defined, scientifically meaningful sample values as 'masked' samples. Wavelet-smoothing is a highly scalable interpolation scheme for regions with complex boundaries on logically rectangular grids. Computation is based on forward/inverse discrete wavelet transforms, so runtime complexity and memory scale linearly with respect to sample count. Efficient state-of-the-art minimal realizations yield small constants (O(10)) for arithmetic complexity scaling, and in-situ implementation techniques make optimal use of memory. Implementation in two dimensions using tensor product filter banks is straighsorward and should generalize routinely to higher dimensions. No hand-tuning required when the interpolation mask changes, making the method aeractive for problems with time-varying masks. Well-suited for interpolating undefined samples prior to JPEG 2000 encoding. The method outperforms global mean interpolation, as judged by both SNR rate-distortion performance and low-rate artifact mitigation, for data distributions whose histograms do not take the form of sharply peaked, symmetric, unimodal probability density functions. These performance advantages can hold even for data whose distribution differs only moderately from the peaked unimodal case, as demonstrated by POP salinity data. The interpolation method is very general and is not tied to any particular class of applications, could be used for more generic smooth interpolation.

  12. Patterned graphene functionalization via mask-free scanning of micro-plasma jet under ambient condition

    SciTech Connect (OSTI)

    Ye, Dong; Yu, Yao, E-mail: ensiyu@mail.hust.edu.cn; Liu, Lin [School of Materials Science and Engineering, Huazhong University of Science and Technology, 430074 Wuhan (China)] [School of Materials Science and Engineering, Huazhong University of Science and Technology, 430074 Wuhan (China); Wu, Shu-Qun; Lu, Xin-Pei [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China)] [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Wu, Yue [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3255 (United States)] [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3255 (United States)

    2014-03-10T23:59:59.000Z

    In this work, a mask-free method is introduced for patterned nitrogen doping of graphene using a micro-plasma jet under ambient condition. Raman and X-ray photoelectron spectroscopy spectra indicate that nitrogen atoms are incorporated into the graphene lattice with the two-dimensional spatial distribution precisely controlled in the range of mm down to 10??m. Since the chemistry of the micro-plasma jet can be controlled by the choice of the gas mixture, this direct writing process with micro-plasma jet can be a versatile approach for patterned functionalization of graphene with high spatial resolution. This could have promising applications in graphene-based electronics.

  13. A CLOSE COMPANION SEARCH AROUND L DWARFS USING APERTURE MASKING INTERFEROMETRY AND PALOMAR LASER GUIDE STAR ADAPTIVE OPTICS

    SciTech Connect (OSTI)

    Bernat, David [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Bouchez, Antonin H.; Cromer, John L.; Dekany, Richard G.; Moore, Anna M. [California Institute of Technology, Pasadena, CA 91125 (United States); Ireland, Michael; Tuthill, Peter [Sydney Institute for Astrophysics, School of Physics, University of Sydney (Australia); Martinache, Frantz [National Astronomical Observatory of Japan, Subaru Telescope, Hilo, HI 96720 (United States); Angione, John; Burruss, Rick S.; Guiwits, Stephen R.; Henning, John R.; Hickey, Jeff; Kibblewhite, Edward; McKenna, Daniel L.; Petrie, Harold L.; Roberts, Jennifer; Shelton, J. Chris; Thicksten, Robert P.; Trinh, Thang [Palomar Laser Guide Star Adaptive Optics Team, Palomar Observatory, California Institute of Technology, Palomar Mountain, CA 92060 (United States)

    2010-06-01T23:59:59.000Z

    We present a close companion search around 16 known early L dwarfs using aperture masking interferometry with Palomar laser guide star adaptive optics (LGS AO). The use of aperture masking allows the detection of close binaries, corresponding to projected physical separations of 0.6-10.0 AU for the targets of our survey. This survey achieved median contrast limits of {Delta}K {approx} 2.3 for separations between 1.2 {lambda}/D-4{lambda}/D and {Delta}K {approx} 1.4 at 2/3 {lambda}/D. We present four candidate binaries detected with moderate-to-high confidence (90%-98%). Two have projected physical separations less than 1.5 AU. This may indicate that tight-separation binaries contribute more significantly to the binary fraction than currently assumed, consistent with spectroscopic and photometric overluminosity studies. Ten targets of this survey have previously been observed with the Hubble Space Telescope as part of companion searches. We use the increased resolution of aperture masking to search for close or dim companions that would be obscured by full aperture imaging, finding two candidate binaries. This survey is the first application of aperture masking with LGS AO at Palomar. Several new techniques for the analysis of aperture masking data in the low signal-to-noise regime are explored.

  14. The effects of fastener hole defects

    E-Print Network [OSTI]

    Andrews, Scot D.

    1991-01-01T23:59:59.000Z

    ) August 1991 ABSTRACT The Effects of Fastener Hole Defects. (August 1991) Scot D. Andrews, B. S. , Texas A8rM University Chair of Advisory Committee: Dr. Orden O. Ochoa The influence of drilling-induced defects, such as delamination, on the fatigue... ambient and elevated temperature wet conditions. Specimens were tested in a bearing tension frame to static failure in order to measure the failure load and to calculate pin bearing stress. From static test results, a fatigue load was selected as 66...

  15. Dirac oscillator interacting with a topological defect

    SciTech Connect (OSTI)

    Carvalho, J.; Furtado, C.; Moraes, F. [Unidade Academica de Tecnologia de Alimentos, CCTA, Universidade Federal de Campina Grande, Pereiros, 58840-000, Pombal, Paraiba (Brazil); Departamento de Fisica, CCEN, Universidade Federal da Paraiba, Cidade Universitaria, 58051-970 Joao Pessoa, Paraiba (Brazil)

    2011-09-15T23:59:59.000Z

    In this work we study the interaction problem of a Dirac oscillator with gravitational fields produced by topological defects. The energy levels of the relativistic oscillator in the cosmic string and in the cosmic dislocation space-times are sensible to curvature and torsion associated to these defects and are important evidence of the influence of the topology on this system. In the presence of a localized magnetic field the energy levels acquire a term associated with the Aharonov-Bohm effect. We obtain the eigenfunctions and eigenvalues and see that in the nonrelativistic limit some results known in standard quantum mechanics are reached.

  16. Bistable defect structures in blue phase devices

    E-Print Network [OSTI]

    A. Tiribocchi; G. Gonnella; D. Marenduzzo; E. Orlandini; F. Salvadore

    2011-10-28T23:59:59.000Z

    Blue phases (BPs) are liquid crystals made up by networks of defects, or disclination lines. While existing phase diagrams show a striking variety of competing metastable topologies for these networks, very little is known as to how to kinetically reach a target structure, or how to switch from one to the other, which is of paramount importance for devices. We theoretically identify two confined blue phase I systems in which by applying an appropriate series of electric field it is possible to select one of two bistable defect patterns. Our results may be used to realise new generation and fast switching energy-saving bistable devices in ultrathin surface treated BPI wafers.

  17. GaN: Defect and Device Issues

    SciTech Connect (OSTI)

    Pearton, S.J.; Ren, F.; Shul, R.J.; Zolper, J.C.

    1998-11-09T23:59:59.000Z

    The role of extended and point defects, and key impurities such as C, O and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.

  18. Ice-assisted electron beam lithography of graphene This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Ice-assisted electron beam lithography of graphene This article has been downloaded from IOPscience PUBLISHING NANOTECHNOLOGY Nanotechnology 23 (2012) 185302 (6pp) doi:10.1088/0957-4484/23/18/185302 Ice demonstrate that a low energy focused electron beam can locally pattern graphene coated with a thin ice layer

  19. Sub-50 nm high aspect-ratio silicon pillars, ridges, and trenches fabricated using ultrahigh resolution electron beam lithography and reactive ion

    E-Print Network [OSTI]

    resolution electron beam lithography and reactive ion etching P. B. Fischer and S. Y. Chou University of Minnesota Department of Electrical Engineering, Minneapolis, Minnesota 554~3 (Received 29 July 1992 and chlorine based reactive ion etching. These nanoscale Si features can be further reduced to 10 nm using

  20. Nanopatterning of Si/SiGe Two-dimensional Hole Gases by PFOTS-aided AFM Lithography of Carrier Supply Layer

    E-Print Network [OSTI]

    Nanopatterning of Si/SiGe Two-dimensional Hole Gases by PFOTS-aided AFM Lithography of Carrier The nanopatterning of Si/SiGe layers by PFOTS (perfluorooctyl trichlorosilane) -aided AFM (atomic force microscopy and then transfer patterns in to underlying SiGe layers by a two-step selective wet etching. Minimum linewidths

  1. Fabrication of Sub-10-nm Silicon Nanowire Arrays by Size Reduction Lithography Yang-Kyu Choi, Ji Zhu,, Jeff Grunes,, Jeffrey Bokor, and Gabor. A. Somorjai*,,

    E-Print Network [OSTI]

    Bokor, Jeffrey

    systems. Introduction The fabrication of nanoscale patterns with dimensions of 10 nm or less has been and space dimensions" from polysilicon (polycrystalline silicon) and a metal oxide by etching one et al. carried out what they called "spacer lithography" to produce electronic devices in silicon

  2. Coulomb screening in graphene with topological defects

    E-Print Network [OSTI]

    Chakraborty, Baishali; Sen, Siddhartha

    2015-01-01T23:59:59.000Z

    We analyze the screening of an external Coulomb charge in gapless graphene cone, which is taken as a prototype of a topological defect. In the subcritical regime, the induced charge is calculated using both the Green's function and the Friedel sum rule. The dependence of the polarization charge on the Coulomb strength obtained from the Green's function clearly shows the effect of the conical defect and indicates that the critical charge itself depends on the sample topology. Similar analysis using the Friedel sum rule indicates that the two results agree for low values of the Coulomb charge but differ for the higher strengths, especially in the presence of the conical defect. For a given subcritical charge, the transport cross-section has a higher value in the presence of the conical defect. In the supercritical regime we show that the coefficient of the power law tail of polarization charge density can be expressed as a summation of functions which vary log periodically with the distance from the Coulomb imp...

  3. Brake Defect Causation and Abatement Study (BDCAS)

    E-Print Network [OSTI]

    on various lining materials for comparison study #12;Center for Transportation Analysis 2360 CherahalaBrake Defect Causation and Abatement Study (BDCAS) Oak Ridge National Laboratory managed by UT Based Brake Testers (PBBTs) part of the out-of- service criterion for commercial motor vehicles in 2007

  4. Atomic-Level Computer Simulation of SiC: Defect Accumulation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic-Level Computer Simulation of SiC: Defect Accumulation, Mechanical Properties and Defect Recovery. Atomic-Level Computer Simulation of SiC: Defect Accumulation, Mechanical...

  5. A Super-high Angular Resolution Principle for Coded-mask X-ray Imaging Beyond the Diffraction Limit of Single Pinhole

    E-Print Network [OSTI]

    Chen Zhang; Shuang Nan Zhang

    2008-06-25T23:59:59.000Z

    High angular resolution X-ray imaging is always demanded by astrophysics and solar physics, which can be realized by coded-mask imaging with very long mask-detector distance in principle. Previously the diffraction-interference effect has been thought to degrade coded-mask imaging performance dramatically at low energy end with very long mask-detector distance. In this work the diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method (DICC) is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle (SHARP) for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of single pinhole is demonstrated with simulations. With the specification that the mask element size of 50* 50 square micrometers and the mask-detector distance of 50 m, the achieved angular resolution is 0.32 arcsec above about 10 keV, and 0.36 arcsec at 1.24 keV where diffraction can not be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also shortly discussed.

  6. Pattern Recognition Pergamon Press 1973. Vol. 5, pp. 199-211. Printed in Great Britain The "Rubber-Mask" Technique II.

    E-Print Network [OSTI]

    Widrow, Bernard

    Pattern Recognition Pergamon Press 1973. Vol. 5, pp. 199-211. Printed in Great Britain The "Rubber to date, and relates the rubber mask technique to previous work. A scheme for incorporating flexible by flexible matching, is also presented. Flexible templates Rubber masks Pattern recognition and memory system

  7. Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten masks: A method to map the free-carrier

    E-Print Network [OSTI]

    Nabben, Reinhard

    Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten properties of two epitaxial-laterally overgrown GaN structures with tungsten masks in 1100 and 1120 direction by tungsten masks3 to prevent the in-diffusion of silicon and oxygen atoms in the overgrown GaN, which

  8. Defect- and Strain-enhanced Cavity Formation and Au Precipitation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Defect- and Strain-enhanced Cavity Formation and Au Precipitation at nano-crystalline ZrO2SiO2Si Interfaces . Defect- and Strain-enhanced Cavity Formation and Au Precipitation at...

  9. Estimating the expected latency to failure due to manufacturing defects 

    E-Print Network [OSTI]

    Dorsey, David Michael

    2004-09-30T23:59:59.000Z

    Manufacturers of digital circuits test their products to find defective parts so they are not sold to customers. Despite extensive testing, some of their products that are defective pass the testing process. To combat ...

  10. Healing of defects in a two-dimensional granular crystal

    E-Print Network [OSTI]

    Rice, Marie C

    2014-01-01T23:59:59.000Z

    Using a macroscopic analog for a two dimensional hexagonal crystal, we perform an experimental investigation of the self-healing properties of circular grain defects with an emphasis on defect orientation. A circular grain ...

  11. Automated Diagnosis and Classification of Steam Generator Tube Defects

    SciTech Connect (OSTI)

    Dr. Gabe V. Garcia

    2004-10-01T23:59:59.000Z

    A major cause of failure in nuclear steam generators is tube degradation. Tube defects are divided into seven categories, one of which is intergranular attack/stress corrosion cracking (IGA/SCC). Defects of this type usually begin on the outer surface of the tubes and propagate both inward and laterally. In many cases these defects occur at or near the tube support plates. Several different methods exist for the nondestructive evaluation of nuclear steam generator tubes for defect characterization.

  12. Collective phenomena in defect crystals Reimer Kuhn1,

    E-Print Network [OSTI]

    Kühn, Reimer

    by quantum effects. Both thermal and dynamical properties are considered. The influence of interactions Talence cedex, France Received 25 April 2000 We investigate the effects of interactions between substitutional defects on the properties of defect crystals at low temperatures, where defect motion is governed

  13. Critical Area Computation for Missing Material Defects in VLSI Circuits

    E-Print Network [OSTI]

    Papadopoulou, Evanthia

    Critical Area Computation for Missing Material Defects in VLSI Circuits Evanthia Papadopoulou IBM the problem of computing critical area for miss- ing material defects in a circuit layout. The extraction of critical area is the main computational problem in VLSI yield prediction. Missing material defects cause

  14. FEATURE ENHANCEMENT USING SPARSE REFERENCE AND ESTIMATED SOFT-MASK EXEMPLAR-PAIRS FOR NOISY SPEECH RECOGNITION

    E-Print Network [OSTI]

    Alwan, Abeer

    FEATURE ENHANCEMENT USING SPARSE REFERENCE AND ESTIMATED SOFT-MASK EXEMPLAR-PAIRS FOR NOISY SPEECH-robust speech recogni- tion is proposed. Existing sparse exemplar-based feature enhance- ment methods use clean speech recognition [14]. More recently in [13], another feature enhancement scheme is pro

  15. ON THE OPTIMALITY OF IDEAL BINARY TIME-FREQUENCY MASKS Yipeng Li and DeLiang Wang

    E-Print Network [OSTI]

    Wang, DeLiang "Leon"

    of Computer Science and Engineering The Ohio State University {liyip, dwang}@cse.ohio-state.edu ABSTRACT also experimentally compare the performance of ideal binary masks in terms of signal-to-noise ratio separation, Wiener filter 1. INTRODUCTION The human auditory system has the ability to segregate an acoustic

  16. Analysis of Mask-Based Nanowire Decoders Eric Rachlin, Student Member, IEEE, and John E. Savage, Life Fellow, IEEE

    E-Print Network [OSTI]

    Savage, John

    is controlling parallel sets of nanowires (NWs), such as those in crossbars, using a moderate number of mesoscale wires. Three similar methods have been proposed to control NWs using a set of perpendicular mesoscale between NWs and mesoscale wires, and the third, a mask-based approach, interposes high-K dielectric

  17. A HIGH ASPECT RATIO, FLEXIBLE, TRANSPARENT AND LOW-COST PARYLENE-C SHADOW MASK TECHNOLOGY FOR MICROPATTERNING APPLICATIONS

    E-Print Network [OSTI]

    Dokmeci, Mehmet

    this shadow mask, we successfully patterned proteins and cells on various surfaces (glass, PDMS, methacrylate) up to 9 times. This technology has potential applications for patterning proteins, cells and organic steps, and lack the precise pattern definition and flexibility to create patterns with varying length

  18. Good Halftone Masks via Genetic Algorithms Peter G. Anderson, Jonathan S. Arney, Samuel A. Inverso, Daniel R. Kunkle,

    E-Print Network [OSTI]

    Anderson, Peter G.

    of relatively poor individuals to keep the popula- tion size constant. It mutates then evaluates the new individuals. This process terminates after a predetermined time or when a satisfactory individual appears. GAs figure of merit ex- presses how well a mask renders a constant gray image--from the point of view

  19. High aspect ratio x-ray waveguide channels fabricated by e-beam lithography and wafer bonding

    SciTech Connect (OSTI)

    Neubauer, H.; Hoffmann, S.; Kanbach, M.; Haber, J.; Kalbfleisch, S.; Krüger, S. P.; Salditt, T., E-mail: tsaldit@gwdg.de [Institut für Röntgenphysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany)

    2014-06-07T23:59:59.000Z

    We report on the fabrication and characterization of hard x-ray waveguide channels manufactured by e-beam lithography, reactive ion etching and wafer bonding. The guiding layer consists of air or vacuum and the cladding material of silicon, which is favorable in view of minimizing absorption losses. The specifications for waveguide channels which have to be met in the hard x-ray range to achieve a suitable beam confinement in two orthogonal directions are extremely demanding. First, high aspect ratios up to 10{sup 6} have to be achieved between lateral structure size and length of the guides. Second, the channels have to be deeply embedded in material to warrant the guiding of the desired modes while absorbing all other (radiative) modes in the cladding material. We give a detailed report on device fabrication with the respective protocols and parameter optimization, the inspection and the optical characterization.

  20. A NEW ALGORITHM FOR RADIOISOTOPE IDENTIFICATION OF SHIELDED AND MASKED SNM/RDD MATERIALS

    SciTech Connect (OSTI)

    Jeffcoat, R.

    2012-06-05T23:59:59.000Z

    Detection and identification of shielded and masked nuclear materials is crucial to national security, but vast borders and high volumes of traffic impose stringent requirements for practical detection systems. Such tools must be be mobile, and hence low power, provide a low false alarm rate, and be sufficiently robust to be operable by non-technical personnel. Currently fielded systems have not achieved all of these requirements simultaneously. Transport modeling such as that done in GADRAS is able to predict observed spectra to a high degree of fidelity; our research is focusing on a radionuclide identification algorithm that inverts this modeling within the constraints imposed by a handheld device. Key components of this work include incorporation of uncertainty as a function of both the background radiation estimate and the hypothesized sources, dimensionality reduction, and nonnegative matrix factorization. We have partially evaluated performance of our algorithm on a third-party data collection made with two different sodium iodide detection devices. Initial results indicate, with caveats, that our algorithm performs as good as or better than the on-board identification algorithms. The system developed was based on a probabilistic approach with an improved approach to variance modeling relative to past work. This system was chosen based on technical innovation and system performance over algorithms developed at two competing research institutions. One key outcome of this probabilistic approach was the development of an intuitive measure of confidence which was indeed useful enough that a classification algorithm was developed based around alarming on high confidence targets. This paper will present and discuss results of this novel approach to accurately identifying shielded or masked radioisotopes with radiation detection systems.

  1. Transmissive optomechanical platforms with engineered spatial defects

    E-Print Network [OSTI]

    Edoardo Tignone; Guido Pupillo; Claudiu Genes

    2014-06-23T23:59:59.000Z

    We investigate the optomechanical photon-phonon coupling of a single light mode propagating through an array of vibrating mechanical elements. As recently shown for the particular case of a periodic array of membranes embedded in a high-finesse optical cavity [A. Xuereb, C. Genes and A. Dantan, Phys. Rev. Lett., \\textbf{109}, 223601, (2012)], the intracavity linear optomechanical coupling can be considerably enhanced over the single element value in the so-called \\textit{transmissive regime}, where for motionless membranes the whole system is transparent to light. Here, we extend these investigations to quasi-periodic arrays in the presence of engineered spatial defects in the membrane positions. In particular we show that the localization of light modes induced by the defect combined with the access of the transmissive regime window can lead to additional enhancement of the strength of both linear and quadratic optomechanical couplings.

  2. Metastable light induced defects in pentacene

    SciTech Connect (OSTI)

    Liguori, R.; Aprano, S.; Rubino, A. [Department of Industrial Engineering (DIIn), University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano (Italy)

    2014-02-21T23:59:59.000Z

    In this study we analyzed one of the environmental factors that could affect organic materials. Pentacene thin film samples were fabricated and the degradation of their electrical characteristics was measured when the devices were exposed to ultraviolet light irradiation. The results have been reported in terms of a trap density model, which provides a description of the dynamics of light induced electrically active defects in an organic semiconductor.

  3. Defect suppression from the compound semiconductor heterointerfaces

    SciTech Connect (OSTI)

    Kalem, S. [TUBITAK-Marmara Research Center, Gebze (Turkey); Curtis, A.; Hartmann, Q.J.; Thomas, S.; Turnbull, D.; Chuang, H.; Bishop, S.G.; Stillman, G.E. [Univ. of Illinois, Urbana, IL (United States). Center for Compound Semiconductor Microelectronics

    1996-12-31T23:59:59.000Z

    The authors report on the effect of inserting ultra-thin InAs layers at the heterointerfaces on physical properties of GaAs/InGaP on GaAs and InP/GaAs on InP grown by MOCVD and MOMBE, respectively. It is shown that the insertion of ultra thin InAs layers at the heterostructure interfaces has a significant effect in eliminating defects from the interfaces.

  4. Topological defects and electronic properties in graphene

    E-Print Network [OSTI]

    Alberto Cortijo; María A. H. Vozmediano

    2006-12-14T23:59:59.000Z

    In this work we will focus on the effects produced by topological disorder on the electronic properties of a graphene plane. The presence of this type of disorder induces curvature in the samples of this material, making quite difficult the application of standard techniques of many body quantum theory. Once we understand the nature of these defects, we can apply ideas belonging to quantum field theory in curved space-time and extract information on physical properties that can be measured experimentally.

  5. Charged Local Defects in Extended Systems

    SciTech Connect (OSTI)

    Schultz, Peter A.

    1999-05-25T23:59:59.000Z

    The conventional approach to treating charged defects in extended systems in first principles calculations is via the supercell approximation using a neutralizing jellium background charge. I explicitly demonstrate shortcomings of this standard approach and discuss the consequences. Errors in the electrostatic potential surface over the volume of a supercell are shown to be comparable to a band gap energy in semiconductor materials, for cell sizes typically used in first principles simulations. I present an alternate method for eliminating the divergence of the Coulomb potential in supercell calculations of charged defects in extended systems that embodies a correct treatment of the electrostatic potential in the local viciniq of the a charged defect, via a mixed boundary condition approach. I present results of first principles calculations of charged vacancies in NaCl that illustrate the importance of polarization effects once an accurate representation of the local potential is obtained. These polarization effects, poorly captured in small supercells, also impact the energetic on the scale of typical band gap energies.

  6. Further investigation of the characteristics of nodular defects

    SciTech Connect (OSTI)

    Liu Xiaofeng; Li Dawei; Zhao Yuan'an; Li Xiao

    2010-04-01T23:59:59.000Z

    To increase the understanding of the damage sensitivity of nodular defects and provide exact evidence for theoretical study, the structures and the damage behavior of nodular defects in electron-beam deposited mirrors of HfO2/SiO2 are systemically investigated with a double-beam microscope (focused ion beam, scanning electron microscope). Nodular defects are classified into two kinds. In one kind the boundaries between nodules and the surrounding layers have become continuous for the last deposited materials, and in the other there are discontinuous boundaries between nodules and the surrounding layers. Nodular defects of the first kind typically have low domes, and the second have high domes. Laser damage experiments show that nodular defects of the first kind usually have a high laser resistance, and the laser-induced damage thresholds are limited in the second class of nodules. The dominant parameter of nodular defects related to damage is the height of the nodular defect.

  7. A single-molecule approach to ZnO defect studies: Single photons and single defects

    SciTech Connect (OSTI)

    Jungwirth, N. R.; Pai, Y. Y.; Chang, H. S.; MacQuarrie, E. R.; Nguyen, K. X.; Fuchs, G. D. [Cornell University, Ithaca, New York 14853 (United States)

    2014-07-28T23:59:59.000Z

    Investigations that probe defects one at a time offer a unique opportunity to observe properties and dynamics that are washed out of ensemble measurements. Here, we present confocal fluorescence measurements of individual defects in ZnO nanoparticles and sputtered films that are excited with sub-bandgap energy light. Photon correlation measurements yield both antibunching and bunching, indicative of single-photon emission from isolated defects that possess a metastable shelving state. The single-photon emission is in the range of ?560–720?nm and typically exhibits two broad spectral peaks separated by ?150?meV. The excited state lifetimes range from 1 to 13?ns, consistent with the finite-size and surface effects of nanoparticles and small grains. We also observe discrete jumps in the fluorescence intensity between a bright state and a dark state. The dwell times in each state are exponentially distributed and the average dwell time in the bright (dark) state does (may) depend on the power of the exciting laser. Taken together, our measurements demonstrate the utility of a single-molecule approach to semiconductor defect studies and highlight ZnO as a potential host material for single-defect based applications.

  8. Method of identifying defective particle coatings

    DOE Patents [OSTI]

    Cohen, Mark E. (San Diego, CA); Whiting, Carlton D. (San Diego, CA)

    1986-01-01T23:59:59.000Z

    A method for identifying coated particles having defective coatings desig to retain therewithin a build-up of gaseous materials including: (a) Pulling a vacuum on the particles; (b) Backfilling the particles at atmospheric pressure with a liquid capable of wetting the exterior surface of the coated particles, said liquid being a compound which includes an element having an atomic number higher than the highest atomic number of any element in the composition which forms the exterior surface of the particle coating; (c) Drying the particles; and (d) Radiographing the particles. By television monitoring, examination of the radiographs is substantially enhanced.

  9. Computer programs for eddy-current defect studies

    SciTech Connect (OSTI)

    Pate, J. R.; Dodd, C. V. [Oak Ridge National Lab., TN (USA)

    1990-06-01T23:59:59.000Z

    Several computer programs to aid in the design of eddy-current tests and probes have been written. The programs, written in Fortran, deal in various ways with the response to defects exhibited by four types of probes: the pancake probe, the reflection probe, the circumferential boreside probe, and the circumferential encircling probe. Programs are included which calculate the impedance or voltage change in a coil due to a defect, which calculate and plot the defect sensitivity factor of a coil, and which invert calculated or experimental readings to obtain the size of a defect. The theory upon which the programs are based is the Burrows point defect theory, and thus the calculations of the programs will be more accurate for small defects. 6 refs., 21 figs.

  10. Physisorption of molecular hydrogen on carbon nanotube with vacant defects

    SciTech Connect (OSTI)

    Sun, Gang; Shen, Huaze; Wang, Enge; Xu, Limei, E-mail: limei.xu@pku.edu.cn [International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Tangpanitanon, Jirawat [University of Cambridge, Cambridge, Cambridgeshire CB2 1TP (United Kingdom); Wen, Bo [International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871 (China); Beijing Computational Science Research Center, Heqing Street, Haidian District, Beijing 100084 (China); Xue, Jianming [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China)

    2014-05-28T23:59:59.000Z

    Physisorption of molecular hydrogen on single-walled carbon nanotubes (SWCNTs) is important for its engineering applications and hydrogen energy storage. Using molecular dynamics simulation, we study the physisorption of molecular hydrogen on a SWCNT with a vacant defect, focusing on the effect of the vacant defect size and external parameters such as temperature and pressure. We find that hydrogen can be physisorbed inside a SWCNT through a vacant defect when the defect size is above a threshold. By controlling the size of the defects, we are able to extract hydrogen molecules from a gas mixture and store them inside the SWCNT. We also find that external parameters, such as low temperature and high pressure, enhance the physisorption of hydrogen molecules inside the SWCNT. In addition, the storage efficiency can be improved by introducing more defects, i.e., reducing the number of carbon atoms on the SWCNT.

  11. On the Defect Group of a 6D SCFT

    E-Print Network [OSTI]

    Michele Del Zotto; Jonathan J. Heckman; Daniel S. Park; Tom Rudelius

    2015-03-16T23:59:59.000Z

    We use the F-theory realization of 6D superconformal field theories (SCFTs) to study the corresponding spectrum of stringlike, i.e. surface defects. On the tensor branch, all of the stringlike excitations pick up a finite tension, and there is a corresponding lattice of string charges, as well as a dual lattice of charges for the surface defects. The defect group is data intrinsic to the SCFT and measures the surface defect charges which are not screened by dynamical strings. When non-trivial, it indicates that the associated theory has a partition vector rather than a partition function. We compute the defect group for all known 6D SCFTs, and find that it is just the abelianization of the discrete subgroup of U(2) which appears in the classification of 6D SCFTs realized in F-theory. We also explain how the defect group specifies defining data in the compactification of a (1,0) SCFT.

  12. Enhanced Software for Displaying Orthographic, Stereographic, Gnomic and Cylindrical Projections of the Sunpath Diagram and Shading Mask Protractor

    E-Print Network [OSTI]

    Oh, K. W.; Haberl, J. S.; Degelman, L. O.

    2000-01-01T23:59:59.000Z

    . INTRODUCTION The sun-path diagram and shading mask protractor are well known graphic formats that have traditionally been used by architects and engineers to analyze whether or not a solar shading device will block direct sunlight on a given point... 1990), SOMBRERO (Schnieders et al. 1997), AWNSHADE (McCluney 1995), SOLAR-2 (Sheu 1986), SUNPATH (McCluney 1995), and SUNSPEC (McCluney 1995) programs. OPAQUE (Abouella and Milne 1990), developed by the Department of Architecture at UCLA, draws a...

  13. Volunteering at Research and Cultural Collections From Egyptian shabti figures to nineteenth century medical waxes, from West African Masks to modern British

    E-Print Network [OSTI]

    Birmingham, University of

    century medical waxes, from West African Masks to modern British landscape paintings, the Research: Basic cleaning and conservation of objects e.g. cleaning and waxing outdoor sculpture Basic remedial

  14. Design of the commissioning filter/mask/window assembly for undulator beamline front ends at the Advanced Photon Source

    SciTech Connect (OSTI)

    Shu, D.; Kuzay, T.M.

    1995-10-20T23:59:59.000Z

    A compact filter/mask/window assembly has been designed for undulator beamline commissioning activity at the Advanced Photon Source beamlines. The assembly consists of one 300-{mu}m graphite filter, one 127-{mu}m CVD diamond filter and two 250-{mu}m beryllium windows. A water-cooled Glidcop fixed mask with a 4.5-mm {times} 4.5-mm output optical aperture and a 0.96-mrad {times} 1.6-mrad beam missteering acceptance is a major part in the assembly. The CVD diamond filter which is mounted on the downstream side of the fixed mask is designed to also function as a transmitting x-ray beam position monitor. The sum signal from the latter can be used to monitor the physical condition of the graphite filter and prevent any possible chain reaction damage to the beryllium windows downstream. In this paper, the design concept as well as the detailed structural design of the commissioning window are presented. Further applications of the commissioning window commissioning window components are also discussed.

  15. A Close Companion Search around L Dwarfs using Aperture Masking Interferometry and Palomar Laser Guide Star Adaptive Optics

    E-Print Network [OSTI]

    Bernat, David; Ireland, Michael; Tuthill, Peter; Martinache, Frantz; Angione, John; Burruss, Rick S; Cromer, John L; Dekany, Richard G; Guiwits, Stephen R; Henning, John R; Hickey, Jeff; Kibblewhite, Edward; McKenna, Daniel L; Moore, Anna M; Petrie, Harold L; Roberts, Jennifer; Shelton, J Chris; Thicksten, Robert P; Trinh, Thang; Tripathi, Renu; Troy, Mitchell; Truong, Tuan; Velur, Viswa; Lloyd, James P

    2010-01-01T23:59:59.000Z

    We present a close companion search around sixteen known early-L dwarfs using aperture masking interferometry with Palomar laser guide star adaptive optics. The use of aperture masking allows the detection of close binaries, corresponding to projected physical separations of 0.6-10.0 AU for the targets of our survey. This survey achieved median contrast limits of Delta_K ~ 2.3 for separations between 1.2 - 4 lambda/D, and Delta_K ~ 1.4 at (2/3)lambda/D. We present four candidate binaries detected with moderate to high confidence (90-98%). Two have projected physical separations less than 1.5 AU. This may indicate that tight-separation binaries contribute more significantly to the binary fraction than currently assumed, consistent with spectroscopic and photometric overluminosity studies. Ten targets of this survey have previously been observed with the Hubble Space Telescope as part of companion searches. We use the increased resolution of aperture masking to search for close or dim companions that would be o...

  16. Simple intrinsic defects in GaAs : numerical supplement.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2012-04-01T23:59:59.000Z

    This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

  17. Irradiation-induced defect clustering and amorphization in silicon...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    guidance on experimental approaches to reveal the onset of these processes. Citation: Weber WJ, and F Gao.2010."Irradiation-induced defect clustering and amorphization in silicon...

  18. The case against scaling defect models of cosmic structure formation

    E-Print Network [OSTI]

    Andreas Albrecht; Richard A. Battye; James Robinson

    1997-07-11T23:59:59.000Z

    We calculate predictions from defect models of structure formation for both the matter and Cosmic Microwave Background (CMB) over all observable scales. Our results point to a serious problem reconciling the observed large-scale galaxy distribution with the COBE normalization, a result which is robust for a wide range of defect parameters. We conclude that standard scaling defect models are in conflict with the data, and show how attempts to resolve the problem by considering non-scaling defects would require radical departures from the standard scaling picture.

  19. Evolution equation of moving defects: dislocations and inclusions

    E-Print Network [OSTI]

    Markenscoff, Xanthippi

    2010-01-01T23:59:59.000Z

    9483-8 ORIGINAL PAPER Evolution equation of moving defects:Springerlink.com Abstract Evolution equations, or equationsof dissipation, and the evolution equation for a plane

  20. Pipe inspection method gives 3D view of OCTG defects

    SciTech Connect (OSTI)

    Kahil, J. (Baker Hughes Tubular Services, Houston, TX (US))

    1990-07-01T23:59:59.000Z

    A new technique for the nondestructive testing of tubulars is presented. It locates small or oblique defects that are currently going undetected.

  1. Sandia Energy - Research Challenge 4: Defect-Carrier Interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    theoretical capabilities. We are using deep-level optical spectroscopy to quantify defect energy levels and densities. Advanced density functional theory is being used to predict...

  2. annealing radiation defects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    is also investigated. Ionel Lazanu; Sorina Lazanu 2002-08-07 6 Radiation Damage in Silicon -Defect Analysis and Detector Properties - Physics Websites Summary:...

  3. Cloud Detection with MODIS, Part I: Improvements in the MODIS Cloud Mask for Collection 5 *Richard A. Frey, Steven A. Ackerman, Yinghui Liu, Kathleen I. Strabala, Hong Zhang,

    E-Print Network [OSTI]

    Sheridan, Jennifer

    Cloud Detection with MODIS, Part I: Improvements in the MODIS Cloud Mask for Collection 5 *Richard.frey@ssec.wisc.edu August 2007 #12;ABSTRACT Significant improvements have been made to the MODIS cloud mask (MOD35 and MYD35 to the 3.9-12 m and 11-12 m cloud tests. More non-MODIS ancillary input data has been added. Land and sea

  4. Nonradiative coherent carrier captures and defect reaction at deep-level defects via phonon-kick mechanism

    SciTech Connect (OSTI)

    Wakita, Masaki; Suzuki, Kei; Shinozuka, Yuzo [Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510 (Japan)

    2014-02-21T23:59:59.000Z

    We simulated the time evolution of electron-lattice coupling mode, and a series of nonradiative carrier captures by a deep-level defect in a semiconductor. For lattice relaxation energy of the order of the band gap, a series of coherent (athermal) electron and hole captures by a defect is possible for high carrier densities, which results in an inflation in the induced lattice vibration, which in turn enhances a defect reaction.

  5. Science & Technology Review September/October 2008

    SciTech Connect (OSTI)

    Bearinger, J P

    2008-07-21T23:59:59.000Z

    This issue has the following articles: (1) Answering Scientists Most Audacious Questions--Commentary by Dona Crawford; (2) Testing the Accuracy of the Supernova Yardstick--High-resolution simulations are advancing understanding of Type Ia supernovae to help uncover the mysteries of dark energy; (3) Developing New Drugs and Personalized Medical Treatment--Accelerator mass spectrometry is emerging as an essential tool for assessing the effects of drugs in humans; (4) Triage in a Patch--A painless skin patch and accompanying detector can quickly indicate human exposure to biological pathogens, chemicals, explosives, or radiation; and (5) Smoothing Out Defects for Extreme Ultraviolet Lithography--A process for smoothing mask defects helps move extreme ultraviolet lithography one step closer to creating smaller, more powerful computer chips.

  6. Simple intrinsic defects in InAs : numerical predictions.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2013-03-01T23:59:59.000Z

    This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.

  7. Scattering of charge carriers in graphene induced by topological defects

    E-Print Network [OSTI]

    J. M. Fonseca; W. A. Moura-Melo; A. R. Pereira

    2011-08-04T23:59:59.000Z

    We study the scattering of graphene quasiparticles by topological defects, represented by holes, pentagons and heptagons. For holes, we found that at low concentration they give a negligible contribution to the resistivity. Whenever pentagons or heptagons are introduced we realize that a fermionic current is scattered by defects.

  8. CHARACTERIZATION OF VIBRATIONINDUCED IMAGE DEFECTS IN INPUT SCANNERS

    E-Print Network [OSTI]

    Wolberg, George

    ) by dynamic errors of gears, timing bets, and motors, and indirectly by structural vibrations induced by gearsCHARACTERIZATION OF VIBRATION­INDUCED IMAGE DEFECTS IN INPUT SCANNERS Robert P. Loce George Wolberg. Keywords: image defects, digital documents, scanned documents, vibrations, motion quality 1. INTRODUCTION

  9. Built-In Self Test (BIST) for Realistic Delay Defects

    E-Print Network [OSTI]

    Tamilarasan, Karthik Prabhu

    2012-02-14T23:59:59.000Z

    with the insertion of test points, BIST is able to achieve high coverage of stuck-at and transition faults. The quality of BIST patterns on small delay defects is an open question. In this work we analyze the application of BIST to small delay defects using resistive...

  10. Defects activated photoluminescence in two-dimensional semiconductors

    E-Print Network [OSTI]

    Wu, Junqiao

    Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, People's Republic of China, 3, Berkeley, California 94720, United States. Point defects in semiconductors can trap free charge carriers

  11. Defect in lung growth* Comparative study of three diagnostic criteria.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Defect in lung growth* Comparative study of three diagnostic criteria. P. DECHELOTTE, A. LABBE, O and fetuses (49 pathological cases and 25 controls) to detect defects in lung growth. In each case lung disease. RA count is low in lung hypoplasia but is not an entirely reliable diagnostic criterion since

  12. Eddy Current Testing for Detecting Small Defects in Thin Films

    SciTech Connect (OSTI)

    Obeid, Simon; Tranjan, Farid M. [Electrical and Computer Engineering Department, UNCC (United States); Dogaru, Teodor [Albany Instruments, 426-O Barton Creek, Charlotte, NC 28262 (United States)

    2007-03-21T23:59:59.000Z

    Presented here is a technique of using Eddy Current based Giant Magneto-Resistance sensor (GMR) to detect surface and sub-layered minute defects in thin films. For surface crack detection, a measurement was performed on a copper metallization of 5-10 microns thick. It was done by scanning the GMR sensor on the surface of the wafer that had two scratches of 0.2 mm, and 2.5 mm in length respectively. In another experiment, metal coatings were deposited over the layers containing five defects with known lengths such that the defects were invisible from the surface. The limit of detection (resolution), in terms of defect size, of the GMR high-resolution Eddy Current probe was studied using this sample. Applications of Eddy Current testing include detecting defects in thin film metallic layers, and quality control of metallization layers on silicon wafers for integrated circuits manufacturing.

  13. Disentangling defects and sound modes in disordered solids

    E-Print Network [OSTI]

    Sven Wijtmans; M. Lisa Manning

    2015-02-05T23:59:59.000Z

    We develop a new method to isolate localized defects from extended vibrational modes in disordered solids. This method augments particle interactions with an artificial potential that acts as a high-pass filter: it preserves small-scale structures while pushing extended vibrational modes to higher frequencies. The low-frequency modes that remain are "bare" defects; they are exponentially localized without the quadrupolar tails associated with elastic interactions. We identify a robust definition for the energy barrier associated with each defect, which is an important parameter in continuum models for plasticity. Surprisingly, we find that the energy barriers associated with "bare" defects are generally higher than those for defects decorated with elastic tails, suggesting that elastic interactions may help to constitutively activate particle rearrangements.

  14. analysis phase exposure: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    measurements and set up test Haddadi, Hamed 2 Dual exposure, two-photon, conformal phase mask lithography for three dimensional silicon inverse woodpile photonic crystals...

  15. Gate dielectric degradation: Pre-existing vs. generated defects

    SciTech Connect (OSTI)

    Veksler, Dmitry, E-mail: Dmitry.Veksler@sematech.org, E-mail: gennadi.bersuker@sematech.org; Bersuker, Gennadi, E-mail: Dmitry.Veksler@sematech.org, E-mail: gennadi.bersuker@sematech.org [SEMATECH Inc., 257 Fuller Rd., Albany, New York 12203 (United States)

    2014-01-21T23:59:59.000Z

    We consider the possibility that degradation of the electrical characteristics of high-k gate stacks under low voltage stresses of practical interest is caused primarily by activation of pre-existing defects rather than generation of new ones. In nFETs in inversion, in particular, defect activation is suggested to be associated with the capture of an injected electron: in this charged state, defects can participate in a fast exchange of charge carriers with the carrier reservoir (substrate or gate electrode) that constitutes the physical process underlying a variety of electrical measurements. The degradation caused by the activation of pre-existing defects, as opposed to that of new defect generation, is both reversible and exhibits a tendency to saturate through the duration of stress. By using the multi-phonon assisted charge transport description, it is demonstrated that the trap activation concept allows reproducing a variety of experimental results including stress time dependency of the threshold voltage, leakage current, charge pumping current, and low frequency noise. Continuous, long-term degradation described by the power law time dependency is shown to be determined by the activation of defects located in the interfacial SiO{sub 2} layer of the high-k gate stacks. The findings of this study can direct process optimization efforts towards reduction of as-grown precursors of the charge trapping defects as the major factor affecting reliability.

  16. Ultrasonic generator and detector using an optical mask having a grating for launching a plurality of spatially distributed, time varying strain pulses in a sample

    DOE Patents [OSTI]

    Maris, Humphrey J. (Barrington, RI)

    2003-01-01T23:59:59.000Z

    A method and a system are disclosed for determining at least one characteristic of a sample that contains a substrate and at least one film disposed on or over a surface of the substrate. The method includes a first step of placing a mask over a free surface of the at least one film, where the mask has a top surface and a bottom surface that is placed adjacent to the free surface of the film. The bottom surface of the mask has formed therein or thereon a plurality of features for forming at least one grating. A next step directs optical pump pulses through the mask to the free surface of the film, where individual ones of the pump pulses are followed by at least one optical probe pulse. The pump pulses are spatially distributed by the grating for launching a plurality of spatially distributed, time varying strain pulses within the film, which cause a detectable change in optical constants of the film. A next step detects a reflected or a transmitted portion of the probe pulses, which are also spatially distributed by the grating. A next step measures a change in at least one characteristic of at least one of reflected or transmitted probe pulses due to the change in optical constants, and a further step determines the at least one characteristic of the sample from the measured change in the at least one characteristic of the probe pulses. An optical mask is also disclosed herein, and forms a part of these teachings.

  17. Ultrasonic generator and detector using an optical mask having a grating for launching a plurality of spatially distributed, time varying strain pulses in a sample

    DOE Patents [OSTI]

    Maris, Humphrey J. (Barrington, RI)

    2002-01-01T23:59:59.000Z

    A method and a system are disclosed for determining at least one characteristic of a sample that contains a substrate and at least one film disposed on or over a surface of the substrate. The method includes a first step of placing a mask over a free surface of the at least one film, where the mask has a top surface and a bottom surface that is placed adjacent to the free surface of the film. The bottom surface of the mask has formed therein or thereon a plurality of features for forming at least one grating. A next step directs optical pump pulses through the mask to the free surface of the film, where individual ones of the pump pulses are followed by at least one optical probe pulse. The pump pulses are spatially distributed by the grating for launching a plurality of spatially distributed, time varying strain pulses within the film, which cause a detectable change in optical constants of the film. A next step detects a reflected or a transmitted portion of the probe pulses, which are also spatially distributed by the grating. A next step measures a change in at least one characteristic of at least one of reflected or transmitted probe pulses due to the change in optical constants, and a further step determines the at least one characteristic of the sample from the measured change in the at least one characteristic of the probe pulses. An optical mask is also disclosed herein, and forms a part of these teachings.

  18. Point defect balance in epitaxial GaSb

    SciTech Connect (OSTI)

    Segercrantz, N., E-mail: natalie.segercrantz@aalto.fi; Slotte, J.; Makkonen, I.; Kujala, J.; Tuomisto, F. [Department of Applied Physics, Aalto University, P.O. Box 14100, FIN-00076 Aalto Espoo (Finland); Song, Y.; Wang, S. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Göteborg (Sweden); State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences 865 Changning Road, Shanghai 200050 (China)

    2014-08-25T23:59:59.000Z

    Positron annihilation spectroscopy in both conventional and coincidence Doppler broadening mode is used for studying the effect of growth conditions on the point defect balance in GaSb:Bi epitaxial layers grown by molecular beam epitaxy. Positron annihilation characteristics in GaSb are also calculated using density functional theory and compared to experimental results. We conclude that while the main positron trapping defect in bulk samples is the Ga antisite, the Ga vacancy is the most prominent trap in the samples grown by molecular beam epitaxy. The results suggest that the p–type conductivity is caused by different defects in GaSb grown with different methods.

  19. Probing graphene defects and estimating graphene quality with optical microscopy

    SciTech Connect (OSTI)

    Lai, Shen [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); Kyu Jang, Sung [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Jae Song, Young, E-mail: yjsong@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Department of Physics, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Lee, Sungjoo, E-mail: leesj@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); College of Information and Communication Engineering, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of)

    2014-01-27T23:59:59.000Z

    We report a simple and accurate method for detecting graphene defects that utilizes the mild, dry annealing of graphene/Cu films in air. In contrast to previously reported techniques, our simple approach with optical microscopy can determine the density and degree of dislocation of defects in a graphene film without inducing water-related damage or functionalization. Scanning electron microscopy, confocal Raman and atomic force microscopy, and X-ray photoelectron spectroscopy analysis were performed to demonstrate that our nondestructive approach to characterizing graphene defects with optimized thermal annealing provides rapid and comprehensive determinations of graphene quality.

  20. Do the Defects Make It Work? Defect Engineering in Pi-Conjugated Polymers and Their Solar Cells: Preprint

    SciTech Connect (OSTI)

    Wang, D.; Reese, M.; Kopidakis N.; Gregg, B. A.

    2008-05-01T23:59:59.000Z

    The charged defect density in common pi-conjugated polymers such as poly(3-hexylthiophene), P3HT, is around 1018 cm-3. Despite, or perhaps because of, this huge defect density, bulk heterojunction solar cells made from these polymers and a C60 derivative such as PCBM exhibit some of the highest efficiencies (~5%) yet obtained in solid state organic photovoltaic cells. We discuss defects in molecular organic semiconductors and in pi-conjugated polymers. These defects can be grouped in two categories, covalent and noncovalent. Somewhat analogous to treating amorphous silicon with hydrogen, we introduce chemical methods to modify the density and charge of the covalent defects in P3HT by treating it with electrophiles such as dimethyl sulfate and nucleophiles such as sodium methoxide. The effects of these treatments on the electrical and photovoltaic properties and stability of organic PV cells is discussed in terms of the change in the number and chemical properties of the defects. Finally, we address the question of whether the efficiency of OPV cells requires the presence of these defects which function as adventitious p-type dopants. Their presence relieves the resistance limitations usually encountered in cleaner organic semiconductors and can create built-in electric fields at junctions.

  1. Defect reaction network in Si-doped InP : numerical predictions.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2013-10-01T23:59:59.000Z

    This Report characterizes the defects in the defect reaction network in silicon-doped, n-type InP deduced from first principles density functional theory. The reaction network is deduced by following exothermic defect reactions starting with the initially mobile interstitial defects reacting with common displacement damage defects in Si-doped InP until culminating in immobile reaction products. The defect reactions and reaction energies are tabulated, along with the properties of all the silicon-related defects in the reaction network. This Report serves to extend the results for intrinsic defects in SAND 2012-3313: %E2%80%9CSimple intrinsic defects in InP: Numerical predictions%E2%80%9D to include Si-containing simple defects likely to be present in a radiation-induced defect reaction sequence.

  2. Topological defect motifs in two-dimensional Coulomb clusters

    E-Print Network [OSTI]

    Radzvilavi?ius, A; 10.1088/0953-8984/23/38/385301

    2012-01-01T23:59:59.000Z

    The most energetically favourable arrangement of low-density electrons in an infinite two-dimensional plane is the ordered triangular Wigner lattice. However, in most instances of contemporary interest one deals instead with finite clusters of strongly interacting particles localized in potential traps, for example, in complex plasmas. In the current contribution we study distribution of topological defects in two-dimensional Coulomb clusters with parabolic lateral confinement. The minima hopping algorithm based on molecular dynamics is used to efficiently locate the ground- and low-energy metastable states, and their structure is analyzed by means of the Delaunay triangulation. The size, structure and distribution of geometry-induced lattice imperfections strongly depends on the system size and the energetic state. Besides isolated disclinations and dislocations, classification of defect motifs includes defect compounds --- grain boundaries, rosette defects, vacancies and interstitial particles. Proliferatio...

  3. Design and process solutions for decreasing vendor defects

    E-Print Network [OSTI]

    Joyce, Michael (Michael Sagar)

    2013-01-01T23:59:59.000Z

    Why do some new initiatives fail while others succeed? This thesis attempts to answer this complex question by investigating the failure of a defect tracking initiative at Amazon and examining how a reintroduction of the ...

  4. Wave propagation in periodic lattices with defects of smaller dimension

    E-Print Network [OSTI]

    A. A. Kutsenko

    2013-05-20T23:59:59.000Z

    The procedure of evaluating of the spectrum for discrete periodic operators perturbed by operators of smaller dimensions is obtained. This result allows to obtain propagative, guided, localised spectra for different kind of physical operators on graphs with defects.

  5. Defect specific maintenance of SG tubes -- How safe is it?

    SciTech Connect (OSTI)

    Cizelj, L.; Mavko, B.; Dvorsek, T. [Jozef Stefan Institute, Ljubljana (Slovenia)

    1997-02-01T23:59:59.000Z

    The efficiency of the defect specific plugging criterion for outside diameter stress corrosion cracking at tube support plates is assessed. The efficiency is defined by three parameters: (1) number of plugged tubes, (2) probability of steam generator tube rupture and (3) predicted accidental leak rate through the defects. A probabilistic model is proposed to quantify the probability of tube rupture, while procedures available in literature were used to define the accidental leak rates. The defect specific plugging criterion was then compared to the performance of traditional (45%) plugging criterion using realistic data from Krsko nuclear power plant. Advantages of the defect specific approach over the traditional one are clearly shown. Some hints on the optimization of safe life of steam generator are also given.

  6. Role of defects in III-nitride based electronics

    SciTech Connect (OSTI)

    HAN,JUNG; MYERS JR.,SAMUEL M.; FOLLSTAEDT,DAVID M.; WRIGHT,ALAN F.; CRAWFORD,MARY H.; LEE,STEPHEN R.; SEAGER,CARLETON H.; SHUL,RANDY J.; BACA,ALBERT G.

    2000-01-01T23:59:59.000Z

    The LDRD entitled ``Role of Defects in III-Nitride Based Devices'' is aimed to place Sandia National Laboratory at the forefront of the field of GaN materials and devices by establishing a scientific foundation in areas such as material growth, defect characterization/modeling, and processing (metalization and etching) chemistry. In this SAND report the authors summarize their studies such as (1) the MOCVD growth and doping of GaN and AlGaN, (2) the characterization and modeling of hydrogen in GaN, including its bonding, diffusion, and activation behaviors, (3) the calculation of energetic of various defects including planar stacking faults, threading dislocations, and point defects in GaN, and (4) dry etching (plasma etching) of GaN (n- and p-types) and AlGaN. The result of the first AlGaN/GaN heterojunction bipolar transistor is also presented.

  7. Liability for Defective Documentation FloridaInstitute of Technology

    E-Print Network [OSTI]

    Liability for Defective Documentation Cem Kaner FloridaInstitute of Technology 150 West University behind its claims. False claims in documentation might subject the manufacturer to liability for breach Engineering]: Distribution, Maintenance and Enhancement ­ documentation. General Terms Documentation, Human

  8. New Composite Silicon-Defect Graphene Anode Architecture

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A New Composite Silicon-Defect Graphene Anode Architecture for High Capacity, High-Rate Li-ion Batteries Xin Zhao, Cary Hayner, Mayfair Kung, and Harold Kung, Northwestern...

  9. Defects and impurities in graphene-like materials

    E-Print Network [OSTI]

    Terrones, Mauricio

    Graphene-like materials could be used in the fabrication of electronic and optoelectronic devices, gas sensors, biosensors, and batteries for energy storage. Since it is almost impossible to work with defect-free or ...

  10. Built-In Self Test (BIST) for Realistic Delay Defects 

    E-Print Network [OSTI]

    Tamilarasan, Karthik Prabhu

    2012-02-14T23:59:59.000Z

    Testing of delay defects is necessary in deep submicron (DSM) technologies. High coverage delay tests produced by automatic test pattern generation (ATPG) can be applied during wafer and package tests, but are difficult ...

  11. Quality improvement and control based on defect reduction

    E-Print Network [OSTI]

    Dai, Qi, M. Eng. Massachusetts Institute of Technology

    2010-01-01T23:59:59.000Z

    This thesis addresses the quality improvement in a printing process at a food packaging company now experiencing hundreds of printing defects. Methodologies of Define, Measure, Analyze, Improve, and Control (DMAIC), and ...

  12. Modeling rough energy landscapes in defected condensed matter

    E-Print Network [OSTI]

    Monasterio Velásquez, Paul Rene

    2010-01-01T23:59:59.000Z

    This dissertation is a computational and theoretical investigation of the behavior of defected condensed matter and its evolution over long time scales. The thesis provides original contributions to the methodology used ...

  13. Role of fluctuations and defects in select condensed matter problems

    E-Print Network [OSTI]

    Pressé, Steve, 1981-

    2008-01-01T23:59:59.000Z

    Defects and fluctuations dominate both static and dynamical properties of systems in the condensed phase. In this work, we focus on three such examples. Firstly, we model the effect of proton fluctuations on the rate of ...

  14. Spin properties of very shallow nitrogen vacancy defects in diamond

    E-Print Network [OSTI]

    Ofori-Okai, Benjamin Kwasi

    We investigate spin and optical properties of individual nitrogen vacancy centers located within 1–10 nm from the diamond surface. We observe stable defects with a characteristic optically detected magnetic-resonance ...

  15. Sandia National Laboratories: Research Challenge 4: Defect-Carrier...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    edge. Note that the density is much higher in the rightmost QW1 closest to the n-type GaN region. Our study of defects involves unique experimental and theoretical capabilities....

  16. Heavy and Overweight Vehicle Defects Interim Report

    SciTech Connect (OSTI)

    Siekmann, Adam [ORNL; Capps, Gary J [ORNL

    2012-12-01T23:59:59.000Z

    The Federal Highway Administration (FHWA), along with the Federal Motor Carrier Safety Administration (FMCSA), has an interest in overweight commercial motor vehicles, how they affect infrastructure, and their impact on safety on the nation s highways. To assist both FHWA and FMCSA in obtaining more information related to this interest, data was collected and analyzed from two separate sources. A large scale nationwide data collection effort was facilitated by the Commercial Vehicle Safety Alliance as part of a special study on overweight vehicles and an additional, smaller set, of data was collected from the state of Tennessee which included a much more detailed set of data. Over a six-month period, 1,873 Level I inspections were performed in 18 different states that volunteered to be a part of this study. Of the 1,873 inspections, a vehicle out-of-service (OOS) violation was found on 44.79% of the vehicles, a rate significantly higher than the national OOS rate of 27.23%. The main cause of a vehicle being placed OOS was brake-related defects, with approximately 30% of all vehicles having an OOS brake violation. Only about 4% of vehicles had an OOS tire violation, and even fewer had suspension and wheel violations. Vehicle weight violations were most common on an axle group as opposed to a gross vehicle weight violation. About two thirds of the vehicles cited with a weight violation were overweight on an axle group with an average amount of weight over the legal limit of about 2,000 lbs. Data collection is scheduled to continue through January 2014, with more potentially more states volunteering to collect data. More detailed data collections similar to the Tennessee data collection will also be performed in multiple states.

  17. Luminescence properties of defects in GaN

    SciTech Connect (OSTI)

    Reshchikov, Michael A.; Morkoc, Hadis [Department of Electrical Engineering and Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States)

    2005-03-15T23:59:59.000Z

    Gallium nitride (GaN) and its allied binaries InN and AIN as well as their ternary compounds have gained an unprecedented attention due to their wide-ranging applications encompassing green, blue, violet, and ultraviolet (UV) emitters and detectors (in photon ranges inaccessible by other semiconductors) and high-power amplifiers. However, even the best of the three binaries, GaN, contains many structural and point defects caused to a large extent by lattice and stacking mismatch with substrates. These defects notably affect the electrical and optical properties of the host material and can seriously degrade the performance and reliability of devices made based on these nitride semiconductors. Even though GaN broke the long-standing paradigm that high density of dislocations precludes acceptable device performance, point defects have taken the center stage as they exacerbate efforts to increase the efficiency of emitters, increase laser operation lifetime, and lead to anomalies in electronic devices. The point defects include native isolated defects (vacancies, interstitial, and antisites), intentional or unintentional impurities, as well as complexes involving different combinations of the isolated defects. Further improvements in device performance and longevity hinge on an in-depth understanding of point defects and their reduction. In this review a comprehensive and critical analysis of point defects in GaN, particularly their manifestation in luminescence, is presented. In addition to a comprehensive analysis of native point defects, the signatures of intentionally and unintentionally introduced impurities are addressed. The review discusses in detail the characteristics and the origin of the major luminescence bands including the ultraviolet, blue, green, yellow, and red bands in undoped GaN. The effects of important group-II impurities, such as Zn and Mg on the photoluminescence of GaN, are treated in detail. Similarly, but to a lesser extent, the effects of other impurities, such as C, Si, H, O, Be, Mn, Cd, etc., on the luminescence properties of GaN are also reviewed. Further, atypical luminescence lines which are tentatively attributed to the surface and structural defects are discussed. The effect of surfaces and surface preparation, particularly wet and dry etching, exposure to UV light in vacuum or controlled gas ambient, annealing, and ion implantation on the characteristics of the defect-related emissions is described.

  18. Ultrasonic Tomography for Detecting and Locating Defects in Concrete Structures

    E-Print Network [OSTI]

    White, Joshua

    2012-07-16T23:59:59.000Z

    ....................................................... 18 Figure 6 Typical C-scans for simulated defects in shotcrete slabs: Specimens D, E, I, and M ............................................................................................... 19 Figure 7 Clay lump slab construction... and shotcrete s labs. Figs. 5 and 6 delaminations, are shown in Figs. 5 and 6. The images in these figures are representative 19 19 Fig. 6. Typical C-scans for simulated defects in shotcrete slabs: Specimens D (top left), E (top right), I (bottom...

  19. Relative projective cover works for Broue's abelian defect group

    E-Print Network [OSTI]

    Thévenaz, Jacques

    University, Chiba, Japan Tue. 22 June, 2010 Joint work with J¨urgen M¨uller and Felix Noeske Brou´e's abelian that A is a block algebra of OG with a defect group P and that AN is a block algebra of ONG(P) which is the Brauer´e's abelian defect group conjecture holds for all primes p and for all block algebras of OG if G = Co3, where

  20. Graphene materials having randomly distributed two-dimensional structural defects

    DOE Patents [OSTI]

    2013-10-08T23:59:59.000Z

    Graphene-based storage materials for high-power battery applications are provided. The storage materials are composed of vertical stacks of graphene sheets and have reduced resistance for Li ion transport. This reduced resistance is achieved by incorporating a random distribution of structural defects into the stacked graphene sheets, whereby the structural defects facilitate the diffusion of Li ions into the interior of the storage materials.

  1. Gradient Improvement by Removal of Identified Local Defects

    SciTech Connect (OSTI)

    R.L. Geng, W.A. Clemens, C.A. Cooper, H. Hayano, K. Watanabe

    2011-07-01T23:59:59.000Z

    Recent experience of ILC cavity processing and testing at Jefferson Lab has shown that some 9-cell cavities are quench limited at a gradient in the range of 15-25 MV/m. Further studies reveal that these quench limits are often correlated with sub-mm sized and highly localized geometrical defects at or near the equator weld. There are increasing evidence to show that these genetic defects have their origin in the material or in the electron beam welding process (for example due to weld irregularities or splatters on the RF surface and welding porosity underneath the surface). A local defect removal method has been proposed at Jefferson Lab by locally re-melting the niobium material. Several 1-cell cavities with known local defects have been treated by using the JLab local e-beam re-melting method, resulting in gradient and Q0 improvement. We also sent 9-cell cavities with known gradient limiting local defects to KEK for local grinding and to FNAL for global mechanical polishing. We report on the results of gradient improvements by removal of local defects in these cavities.

  2. Crystal defect studies using x-ray diffuse scattering

    SciTech Connect (OSTI)

    Larson, B.C.

    1980-01-01T23:59:59.000Z

    Microscopic lattice defects such as point (single atom) defects, dislocation loops, and solute precipitates are characterized by local electronic density changes at the defect sites and by distortions of the lattice structure surrounding the defects. The effect of these interruptions of the crystal lattice on the scattering of x-rays is considered in this paper, and examples are presented of the use of the diffuse scattering to study the defects. X-ray studies of self-interstitials in electron irradiated aluminum and copper are discussed in terms of the identification of the interstitial configuration. Methods for detecting the onset of point defect aggregation into dislocation loops are considered and new techniques for the determination of separate size distributions for vacancy loops and interstitial loops are presented. Direct comparisons of dislocation loop measurements by x-rays with existing electron microscopy studies of dislocation loops indicate agreement for larger size loops, but x-ray measurements report higher concentrations in the smaller loop range. Methods for distinguishing between loops and three-dimensional precipitates are discussed and possibilities for detailed studies considered. A comparison of dislocation loop size distributions obtained from integral diffuse scattering measurements with those from TEM show a discrepancy in the smaller sizes similar to that described above.

  3. A detail study of defect models for cosmic structure formation

    E-Print Network [OSTI]

    A. Albrecht; R. A. Battye; J. Robinson

    1997-11-27T23:59:59.000Z

    We calculate predictions from wide class of `active' models of cosmic structure formation which allows us to scan the space of possible defect models. We calculate the linear cold dark matter power spectrum and Cosmic Microwave Background (CMB) anisotropies over all observable scales using a full linear Einstein-Boltzmann code. Our main result, which has already been reported, points to a serious problem reconciling the observed amplitude of the large-scale galaxy distribution with the COBE normalization. Here, we describe our methods and results in detail. The problem is present for a wide range of defect parameters, which can be used to represent potential differences among defect models, as well as possible systematic numerical errors. We explicitly examine the impact of varying the defect model parameters and we show how the results substantiate these conclusions. The standard scaling defect models are in serious conflict with the current data, and we show how attempts to resolve the problem by considering non-scaling defects or modified stress-energy components would require radical departures from what has become the standard picture.

  4. Systems and methods for forming defects on graphitic materials and curing radiation-damaged graphitic materials

    DOE Patents [OSTI]

    Ryu, Sunmin; Brus, Louis E.; Steigerwald, Michael L.; Liu, Haitao

    2012-09-25T23:59:59.000Z

    Systems and methods are disclosed herein for forming defects on graphitic materials. The methods for forming defects include applying a radiation reactive material on a graphitic material, irradiating the applied radiation reactive material to produce a reactive species, and permitting the reactive species to react with the graphitic material to form defects. Additionally, disclosed are methods for removing defects on graphitic materials.

  5. Defect studies in low-temperature-grown GaAs

    SciTech Connect (OSTI)

    Bliss, D.E.

    1992-11-01T23:59:59.000Z

    High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V[sub Ga]. The neutral AsGa-related defects were measured by infrared absorption at 1[mu]m. Gallium vacancies, V[sub Ga], was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10[sup 19] cm[sup [minus]3] Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As[sub Ga] in the layer. As As[sub Ga] increases, photoquenchable As[sub Ga] decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As[sub Ga] content around 500C, similar to irradiation damaged and plastically deformed Ga[sub As], as opposed to bulk grown GaAs in which As[sub Ga]-related defects are stable up to 1100C. The lower temperature defect removal is due to V[sub Ga] enhanced diffusion of As[sub Ga] to As precipitates. The supersaturated V[sub GA] and also decreases during annealing. Annealing kinetics for As[sub Ga]-related defects gives 2.0 [plus minus] 0.3 eV and 1.5 [plus minus] 0.3 eV migration enthalpies for the As[sub Ga] and V[sub Ga]. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As[sub Ga]-related defects anneal with an activation energy of 1.1 [plus minus] 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As[sub Ga]-Be[sub Ga] pairs. Si donors can only be partially activated.

  6. Growth of individual carbon nanotubes on an array of TiN/Ni nanodots patterned by e-beam lithography and defined by dry etching for field emission application.

    E-Print Network [OSTI]

    Boyer, Edmond

    or nanoimprint lithography 11 with lift-off. After realizing holes in a resin layer, a TiN film (acting is critical in particular for sputtered layers. Moreover, the deposited TiN film contains carbon and oxygen was employed to etch hal-00880711,version1-8Nov2013 #12;Ni and TiN layers. Following the stripping of HSQ

  7. Climatic isotope signals in tree rings masked by air pollution: A case study conducted along the Mont Blanc Tunnel access road (Western Alps, Italy)

    E-Print Network [OSTI]

    Climatic isotope signals in tree rings masked by air pollution: A case study conducted along, Switzerland h i g h l i g h t s air pollution on the climatic signal recorded in the d13 C chronologies. Air pollution loads strongly influence the photosynthetic process.

  8. Pattern Recognition Pergamon Press 1973. Vol, 5, pp. 175-197. Printed in Great Britain The "Rubber-Mask" Technique I.

    E-Print Network [OSTI]

    Widrow, Bernard

    Pattern Recognition Pergamon Press 1973. Vol, 5, pp. 175-197. Printed in Great Britain The "Rubber in size, fuzzy, rotated, translated, observed at an unusual perspective, etc. Flexible templates (rubber, and electroencephalogram waveforms are illustrated. The rubber-mask technique will probably be usable in a wide variety

  9. Structure, defects, and strain in silicon-silicon oxide interfaces

    SciTech Connect (OSTI)

    Kova?evi?, Goran, E-mail: gkova@irb.hr; Pivac, Branko [Department of Materials Physics, Rudjer Boskovic Institute, Bijeni?ka 56, P.O.B. 180, HR-10002 Zagreb (Croatia)

    2014-01-28T23:59:59.000Z

    The structure of the interfaces between silicon and silicon-oxide is responsible for proper functioning of MOSFET devices while defects in the interface can deteriorate this function and lead to their failure. In this paper we modeled this interface and characterized its defects and strain. MD simulations were used for reconstructing interfaces into a thermodynamically stable configuration. In all modeled interfaces, defects were found in the form of three-coordinated silicon atom, five coordinated silicon atom, threefold-coordinated oxygen atom, or displaced oxygen atom. Three-coordinated oxygen atom can be created if dangling bonds on silicon are close enough. The structure and stability of three-coordinated silicon atoms (P{sub b} defect) depend on the charge as well as on the electric field across the interface. The negatively charged P{sub b} defect is the most stable one, but the electric field resulting from the interface reduces that stability. Interfaces with large differences in periodic constants of silicon and silicon oxide can be stabilized by buckling of silicon layer. The mechanical stress resulted from the interface between silicon and silicon oxide is greater in the silicon oxide layer. Ab initio modeling of clusters representing silicon and silicon oxide shows about three time larger susceptibility to strain in silicon oxide than in silicon if exposed to the same deformation.

  10. Predicting the Occurrence of Cosmetic Defects in Automotive Skin Panels

    SciTech Connect (OSTI)

    Hazra, S.; Williams, D.; Roy, R. [University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Aylmore, R.; Allen, M.; Hollingdale, D. [Land Rover, Banbury Rd, Gaydon, Warwick, CV35 0RR (United Kingdom)

    2011-05-04T23:59:59.000Z

    The appearance of defects such as 'hollows' and 'shock lines' can affect the perceived quality and attractiveness of automotive skin panels. These defects are the result of the stamping process and appear as small, localized deviations from the intended styling of the panels. Despite their size, they become visually apparent after the application of paint and the perceived quality of a panel may become unacceptable. Considerable time is then dedicated to minimizing their occurrence through tool modifications. This paper will investigate the use of the wavelet transform as a tool to analyze physically measured panels. The transform has two key aspects. The first is its ability to distinguish small scale local defects from large scale styling curvature. The second is its ability to characterize the shape of a defect in terms of its wavelength and a 'correlation value'. The two features of the transform enable it to be used as a tool for locating and predicting the severity of defects. The paper will describe the transform and illustrate its application on test cases.

  11. Developmental defects in zebrafish for classification of EGF pathway inhibitors

    SciTech Connect (OSTI)

    Pruvot, Benoist; Curé, Yoann; Djiotsa, Joachim; Voncken, Audrey; Muller, Marc, E-mail: m.muller@ulg.ac.be

    2014-01-15T23:59:59.000Z

    One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairment of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway. In conclusion, we show that developmental indicators can help to discriminate between specific effects on the target pathway from off-target effects in molecularly targeted drug screening experiments in whole animal systems. - Highlights: • We analyze the functions of Egf signaling on zebrafish development. • Genetic blocking of Egf expression causes cartilage, myelin and circulatory defects. • Chemical inhibition of Egf receptor function causes similar defects. • Developmental defects can reveal the specificity of Egf pathway inhibitors.

  12. Solvent Immersion Imprint Lithography

    SciTech Connect (OSTI)

    Vasdekis, Andreas E.; Wilkins, Michael J.; Grate, Jay W.; Kelly, Ryan T.; Konopka, Allan; Xantheas, Sotiris S.; Chang, M. T.

    2014-06-21T23:59:59.000Z

    The mechanism of polymer disolution was explored for polymer microsystem prototyping, including microfluidics and optofluidics. Polymer films are immersed in a solvent, imprinted and finally brought into contact with a non-modified surface to permanently bond. The underlying polymer-solvent interactions were experimentally and theoretically investigated, and enabled rapid polymer microsystem prototyping. During imprinting, small molecule integration in the molded surfaces was feasible, a principle applied to oxygen sensing. Polystyrene (PS) was employed for microbiological studies at extreme environmental conditions. The thermophile anaerobe Clostridium Thermocellum was grown in PS pore-scale micromodels, revealing a double mean generation lifetime than under ideal culture conditions. Microsystem prototyping through directed polymer dissolution is simple and accessible, while simultaneous patterning, bonding, and surface/volume functionalization are possible in less than one minute.

  13. Advances in Lithography

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWP Related LinksATHENAAdministrative80-AAAdvancedof

  14. Ultrasonic imaging system for in-process fabric defect detection

    DOE Patents [OSTI]

    Sheen, Shuh-Haw (Naperville, IL); Chien, Hual-Te (Naperville, IL); Lawrence, William P. (Downers Grove, IL); Raptis, Apostolos C. (Downers Grove, IL)

    1997-01-01T23:59:59.000Z

    An ultrasonic method and system are provided for monitoring a fabric to identify a defect. A plurality of ultrasonic transmitters generate ultrasonic waves relative to the fabric. An ultrasonic receiver means responsive to the generated ultrasonic waves from the transmitters receives ultrasonic waves coupled through the fabric and generates a signal. An integrated peak value of the generated signal is applied to a digital signal processor and is digitized. The digitized signal is processed to identify a defect in the fabric. The digitized signal processing includes a median value filtering step to filter out high frequency noise. Then a mean value and standard deviation of the median value filtered signal is calculated. The calculated mean value and standard deviation are compared with predetermined threshold values to identify a defect in the fabric.

  15. Apparatus and method for defect testing of integrated circuits

    SciTech Connect (OSTI)

    Cole, E.I. Jr.; Soden, J.M.

    2000-02-29T23:59:59.000Z

    An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V(DD), to an IC under test and measures a transient voltage component, V(DDT), signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V(DDT) signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V(DDT) signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.

  16. Apparatus and method for defect testing of integrated circuits

    DOE Patents [OSTI]

    Cole, Jr., Edward I. (Albuquerque, NM); Soden, Jerry M. (Placitas, NM)

    2000-01-01T23:59:59.000Z

    An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V.sub.DD, to an IC under test and measures a transient voltage component, V.sub.DDT, signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V.sub.DDT signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V.sub.DDT signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.

  17. Application of a Theory for Generation of Soft X-Ray by Storage Rings and Its Use For X-Ray Lithography

    SciTech Connect (OSTI)

    Minkov, D. [21st Century COE SLLS (Japan); Yamada, H. [21st Century COE SLLS (Japan); Ritsumeikan University (Japan); PPL Co. Ltd., 1-1-1 Nojihigashi, Kusatsu City, Shiga 525-8577 (Japan); Toyosugi, N.; Morita, M. [PPL Co. Ltd., 1-1-1 Nojihigashi, Kusatsu City, Shiga 525-8577 (Japan); Yamaguchi, T. [Ritsumeikan University (Japan)

    2007-01-19T23:59:59.000Z

    A theory has been developed for generation of soft X-ray transition radiation (TR) by storage ring synchrotrons. It takes into consideration that the dielectric constant of the TR target material is a complex number, utilizes an explicit expression for the number of passes of an injected electron through the target, and describes more precisely the absorption of TR in the target. Such TR can be used for performing X-ray lithography (XRL), and therefore a formula is included for the sensitivity of the photoresist used in XRL. TR targets for XRL can be optimized, based on finding a maximum of the resist sensitivity. Application of this theory to optimization of Mg target shows that a target containing only one Mg foil, with a thickness of about 245 nm is the best Mg target, for performing XRL by our storage ring synchrotron MIRRORCLE-20SX.

  18. I{sub DDQ} Testing and Defect Classes: A Tutorial

    SciTech Connect (OSTI)

    Soden, J.M. [Sandia National Labs., Albuquerque, NM (United States); Hawkins, C.F. [New Mexico State Univ., Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering

    1994-12-31T23:59:59.000Z

    I{sub DDQ} testing of CMOSICs is a technique for production quality and reliability improvement, design validation, and failure analysis. The origin and basic concepts of I{sub DDQ} testing are reviewed. The relationship of I{sub DDQ} testing to other test methods is considered in the context of the whole IC life cycle from design, fabrication, and test through end use. A comprehensive test strategy is described that uses defect classes based on defect electrical properties rather than traditional fault models.

  19. Multi-level scanning method for defect inspection

    DOE Patents [OSTI]

    Bokor, Jeffrey (Oakland, CA); Jeong, Seongtae (Richmond, CA)

    2002-01-01T23:59:59.000Z

    A method for performing scanned defect inspection of a collection of contiguous areas using a specified false-alarm-rate and capture-rate within an inspection system that has characteristic seek times between inspection locations. The multi-stage method involves setting an increased false-alarm-rate for a first stage of scanning, wherein subsequent stages of scanning inspect only the detected areas of probable defects at lowered values for the false-alarm-rate. For scanning inspection operations wherein the seek time and area uncertainty is favorable, the method can substantially increase inspection throughput.

  20. On the material geometry of continuously defective corrugated graphene sheets

    E-Print Network [OSTI]

    Andrzej Trzesowski

    2014-12-22T23:59:59.000Z

    Geometrical objects describing the material geometry of continuously defective graphene sheets are introduced and their compatibility conditions are formulated. Effective edge dislocations embedded in the Riemann-Cartan material space and defined by their scalar density and by local Burgers vectors, are considered. The case of secondary curvature-type defects created by this distribution of dislocations is analysed in terms of the material space. The variational geometry of the material space closely related with the existence of a characteristic length parameter is proposed. The formula which describes, in a reference temperature, the influence of dislocations on the material Riemannian metric, is given.

  1. Positive muon and the positron as probes of defects

    SciTech Connect (OSTI)

    Lynn, K G

    1980-01-01T23:59:59.000Z

    The positive muon and the positron are each being used nowadays to investigate defects in condensed matter. A brief summary of the experimental methods employed with each particle is given in this paper. Similarities and differences between the behavior of the two leptons when implanted in consensed matter are pointed out, and by means of a comparison between muon and positron data in Al it is shown that the combination of muon and positron experiments can serve as a useful new probe of defects in solids.

  2. On the defect induced gauge and Yukawa fields in graphene

    E-Print Network [OSTI]

    Corneliu Sochichiu

    2011-03-08T23:59:59.000Z

    We consider lattice deformations (both continuous and topological) in the hexagonal lattice Hubbard model in the tight binding approximation to graphene, involving operators with the range up to next-to-neighbor. In the low energy limit, we find that these deformations give rise to couplings of the electronic Dirac field to an external scalar (Yukawa) and gauge fields. The fields are expressed in terms of original defects. As a by-product we establish that the next-to-nearest order is the minimal range of deformations which produces the complete gauge and scalar fields. We consider an example of Stone--Wales defect, and find the associated gauge field.

  3. Automatic Detection of Defects in Riveted Lapjoints using Eddy Current

    E-Print Network [OSTI]

    Automatic Detection of Defects in Riveted Lap­joints using Eddy Current Fredrik Lingvall Tadeusz originating from rivet holes in a riveted lap­joint using eddy current (EC) inspection is presented consisted of median filtering, rotation and de­biasing of the eddy current pattern. The rotation

  4. Nature of Radiation-Induced Defects in Quartz

    E-Print Network [OSTI]

    Bu Wang; Yingtian Yu; Isabella Pignatelli; Gaurav N. Sant; Mathieu Bauchy

    2015-04-10T23:59:59.000Z

    Although quartz ($\\rm \\alpha$-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage have not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics (MD) simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si--O connectivity defects, e.g., small Si--O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on $E^{\\prime}$ centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependence on the incident energy, of the amount of each type of the point defects formed, and quantify unambiguously the threshold displacement energies for both O and Si atoms. These results provide a comprehensive basis to assess the nature and extent of radiation damage in quartz.

  5. Preparation and characterization of low-defect surfaces

    SciTech Connect (OSTI)

    Robinson, T.O.

    1991-12-01T23:59:59.000Z

    Silver crystal surfaces with low defect densities were prepared electrochemically from aqueous solutions using capillary-growth techniques. These surfaces had low rates for the nucleation of new silver layers. The impedance of these inert silver/aqueous silver nitrate interfaces was used to determine silver adatom concentration and water dipole reorientation energetics.

  6. Graphene defect formation by extreme ultraviolet generated photoelectrons

    SciTech Connect (OSTI)

    Gao, A., E-mail: a.gao@utwente.nl; Lee, C. J.; Bijkerk, F. [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands and XUV Optics Group, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands)

    2014-08-07T23:59:59.000Z

    We have studied the effect of photoelectrons on defect formation in graphene during extreme ultraviolet (EUV) irradiation. Assuming the major role of these low energy electrons, we have mimicked the process by using low energy primary electrons. Graphene is irradiated by an electron beam with energy lower than 80?eV. After e-beam irradiation, it is found that the D peak, I(D), appears in the Raman spectrum, indicating defect formation in graphene. The evolution of I(D)/I(G) follows the amorphization trajectory with increasing irradiation dose, indicating that graphene goes through a transformation from microcrystalline to nanocrystalline and then further to amorphous carbon. Further, irradiation of graphene with increased water partial pressure does not significantly change the Raman spectra, which suggests that, in the extremely low energy range, e-beam induced chemical reactions between residual water and graphene are not the dominant mechanism driving defect formation in graphene. Single layer graphene, partially suspended over holes was irradiated with EUV radiation. By comparing with the Raman results from e-beam irradiation, it is concluded that the photoelectrons, especially those from the valence band, contribute to defect formation in graphene during irradiation.

  7. Nickel assisted healing of defective graphene S. Karoui,1

    E-Print Network [OSTI]

    Boyer, Edmond

    Nickel assisted healing of defective graphene S. Karoui,1 H. Amara,1 C. Bichara,2 and F. Ducastelle suggesting that their healing are thermally activated. We show that in presence of a nickel substrate we obtain a perfect graphene layer. The nickel-carbon chemical bonds keep breaking and reforming around

  8. Predicting Software Defects in Varying Development Lifecycles using Bayesian Nets

    E-Print Network [OSTI]

    Fenton, Norman

    Predicting Software Defects in Varying Development Lifecycles using Bayesian Nets Norman Fenton, this has required a custom- built BN for each software development lifecycle. We describe a more general BN software development lifecycle ­ to reflect both the differing number of testing stages in the lifecycle

  9. Symmetry Breaking and Topological Defect Formation in Ion Coulomb Crystals

    E-Print Network [OSTI]

    Pyka, Karsten; Partner, Heather L; Nigmatullin, Ramil; Burgermeister, Tobias; Meier, David-M; Kuhlmann, Kristijan; Retzker, Alex; Plenio, Martin B; Zurek, Wojciech H; del Campo, Adolfo; Mehlstäubler, Tanja E

    2013-01-01T23:59:59.000Z

    Symmetry breaking phase transitions play an important role in nature. When a system traverses such a transition at a finite rate, its causally disconnected regions choose the new broken symmetry state independently. Where such local choices are incompatible, defects will form with densities predicted to follow a power law scaling in the rate of the transition. The importance of this Kibble-Zurek mechanism (KZM) ranges from cosmology to condensed matter [1-4]. In previous tests in homogeneous systems, defect formation was seen, but weak dependence on the transition rate and limited control of external parameters so far prevented tests of KZM scaling. As recently predicted [5-9], in inhomogeneous systems propagation of the critical front enhances the role of causality and steepens scaling of defect density with the transition rate. We use ion Coulomb crystals in a harmonic trap to demonstrate, for the first time, scaling of the number of topological defects with the transition rate - the central prediction of K...

  10. On the conservation of software defect CISM, University of Kingston

    E-Print Network [OSTI]

    Hatton, Les

    , T the temperature and R the gas constant is astonishingly accurate over a very wide range of pressures, then commonly used defect models for individual components directly im- ply that the distribution of component systems extremely accurately. For example, for a gas, PV = RT where P is the pressure, V the volume

  11. Spacetime Defects: von Kármán vortex street like configurations

    E-Print Network [OSTI]

    Patricio S. Letelier

    2001-07-05T23:59:59.000Z

    A special arrangement of spinning strings with dislocations similar to a von K\\'arm\\'an vortex street is studied. We numerically solve the geodesic equations for the special case of a test particle moving along twoinfinite rows of pure dislocations and also discuss the case of pure spinning defects.

  12. Applying a tapered electrode on a porous ceramic support tube by masking a band inside the tube and drawing in electrode material from the outside of the tube by suction

    DOE Patents [OSTI]

    Vasilow, T.R.; Zymboly, G.E.

    1991-12-17T23:59:59.000Z

    An electrode is deposited on a support by providing a porous ceramic support tube having an open end and closed end; masking at least one circumferential interior band inside the tube; evacuating air from the tube by an evacuation system, to provide a permeability gradient between the masked part and unmasked part of the tube; applying a liquid dispersion of solid electrode particles to the outside surface of the support tube, where liquid flows through the wall, forming a uniform coating over the unmasked support part and a tapered coating over the masked part. 2 figures.

  13. Atomic Computer Simulations of Defect Migration in 3C and 4H...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Computer Simulations of Defect Migration in 3C and 4H-SiC. Atomic Computer Simulations of Defect Migration in 3C and 4H-SiC. Abstract: Knowledge of the migration of intrinsic point...

  14. Characterization of Defects in N-type 4H-SiC After High-Energy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Characterization of Defects in N-type 4H-SiC After High-Energy N Ion Implantation by RBS-Channeling and Raman Spectroscopy. Characterization of Defects in N-type 4H-SiC After...

  15. First-principles study of defects and phase transition in UO2...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    defects and phase transition in UO2. First-principles study of defects and phase transition in UO2. Abstract: The electronic properties, structure and phase transformation of UO2...

  16. Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons

    E-Print Network [OSTI]

    Tongay, Sefaattin

    Point defects in semiconductors can trap free charge carriers and localize excitons. The interaction between these defects and charge carriers becomes stronger at reduced dimensionalities, and is expected to greatly influence ...

  17. Investigation of Microstructure and V-defect Formation in InxGa...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microstructure and V-defect Formation in InxGa-xNGaN MQW Grown using Temperature-Gradient Metalorganic Investigation of Microstructure and V-defect Formation in InxGa-xNGaN MQW...

  18. Hydrogen Sensing and Sensitivity of Palladium-Decorated Single-Walled Carbon Nanotubes with Defects

    E-Print Network [OSTI]

    Collins, Philip G

    2010-01-01T23:59:59.000Z

    pubs.acs.org/NanoLett Hydrogen Sensing and Sensitivity ofsite. KEYWORDS Carbon nanotube, hydrogen sensor, defect S

  19. EFFECTS OF MANUFACTURING DEFECTS ON THE STRENGTH OF TOUGHENED CARBON/EPOXY PREPREG COMPOSITES

    E-Print Network [OSTI]

    EFFECTS OF MANUFACTURING DEFECTS ON THE STRENGTH OF TOUGHENED CARBON/EPOXY PREPREG COMPOSITES .......................................................................................11 Toughened Resin Systems

  20. Improvements in Near-Terminator and Nocturnal Cloud Masks using Satellite Imager Data over the Atmospheric Radiation Measurement Sites

    SciTech Connect (OSTI)

    Trepte, Q.Z.; Minnis, P.; Heck, P.W.; Palikonda, R.

    2005-03-18T23:59:59.000Z

    Cloud detection using satellite measurements presents a big challenge near the terminator where the visible (VIS; 0.65 {micro}m) channel becomes less reliable and the reflected solar component of the solar infrared 3.9-{micro}m channel reaches very low signal-to-noise ratio levels. As a result, clouds are underestimated near the terminator and at night over land and ocean in previous Atmospheric Radiation Measurement (ARM) Program cloud retrievals using Geostationary Operational Environmental Satellite (GOES) imager data. Cloud detection near the terminator has always been a challenge. For example, comparisons between the CLAVR-x (Clouds from Advanced Very High Resolution Radiometer [AVHRR]) cloud coverage and Geoscience Laser Altimeter System (GLAS) measurements north of 60{sup o}N indicate significant amounts of missing clouds from AVHRR because this part of the world was near the day/night terminator viewed by AVHRR. Comparisons between MODIS cloud products and GLAS at the same regions also shows the same difficulty in the MODIS cloud retrieval (Pavolonis and Heidinger 2005). Consistent detection of clouds at all times of day is needed to provide reliable cloud and radiation products for ARM and other research efforts involving the modeling of clouds and their interaction with the radiation budget. To minimize inconsistencies between daytime and nighttime retrievals, this paper develops an improved twilight and nighttime cloud mask using GOES-9, 10, and 12 imager data over the ARM sites and the continental United States (CONUS).

  1. Equilibrium Defects and Concentrations in Nickel Aluminide Bin Bai* and Gary S. Collins

    E-Print Network [OSTI]

    Collins, Gary S.

    used in aerospace applications. Knowledge of its point defects is needed to understand phenomena by structural point defects: Ni-vacancies (VNi) in Ni-poor alloys and Ni-antisite atoms (NiAl) in Ni-rich alloys at temperatures up to 1300°C. Observation of VNi and NiAl structural defects in Ni-poor and Ni-rich alloys

  2. DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE Submitted by Pamela K ENTITLED THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE BE ACCEPTED AS FULFILLING IN PART RE OF DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE The relationship between basic solar-cell

  3. AUTOMATIC DETECTION AND CLASSIFICATION OF DEFECT ON ROAD PAVEMENT USING ANISOTROPY MEASURE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    AUTOMATIC DETECTION AND CLASSIFICATION OF DEFECT ON ROAD PAVEMENT USING ANISOTROPY MEASURE Tien Sy-sy.nguyen@etu.univ-orleans.fr ABSTRACT Existing systems for automated pavement defect detection can only identify cracking type defects for the inspectors and road users [1]. In the last few years, several automated pavement inspecting systems which use

  4. Defects in Ge and Si caused by 1 MeV Si+ implantation*

    E-Print Network [OSTI]

    Florida, University of

    Defects in Ge and Si caused by 1 MeV Si+ implantation* D. P. Hickeya Department of Materials defect formation and evolution in the 001 Ge and Si wafers implanted with 1 MeV Si+ and 40 keV Si dissolve at the projected range for nonamorphizing implants into Si. However, in Ge, no 311 defect

  5. Effect of Niobium on the Defect Chemistry and Oxidation Kinetics of Tetragonal ZrO2

    E-Print Network [OSTI]

    Yildiz, Bilge

    Effect of Niobium on the Defect Chemistry and Oxidation Kinetics of Tetragonal ZrO2 Uuganbayar, Massachusetts 02139, United States ABSTRACT: Zirconium-niobium alloys are currently proposed for applications the effect of an extrinsic defect, niobium (Nb) dopant, on the defect equilibria and charge transfer

  6. Polarized Luminescence of Defects in CuGaSe2 Susanne Siebentritt1,2

    E-Print Network [OSTI]

    Rockett, Angus

    ). But for the whole group of I-III-VI2 chalcopyrite semiconductors no reliable identification of native defects by ESR been found in CuInSe2. [14] In the effort of relating the energy positions of the defects to defect. Res. Soc. Symp. Proc. Vol. 1012 © 2007 Materials Research Society 1012-Y13-01 #12;the experiment

  7. Oxygen sublattice defect in cobalt oxide : formation, migration, charge localization and thermodynamic processes

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    643 Oxygen sublattice defect in cobalt oxide : formation, migration, charge localization of oxygen defects in CoO using classical simulations. The charge localization in the oxygen vacancy has]. The defect concentration in the oxygen sublattice is several orders of magnitude smaller, but never- theless

  8. Defect production in tungsten: A comparison between field-ion microscopy and molecular-dynamics simulations

    E-Print Network [OSTI]

    Nordlund, Kai

    Defect production in tungsten: A comparison between field-ion microscopy and molecular defect production efficiencies obtained by FIM are a consequence of a surface effect, which greatly enhances defect production compared to that in the crystal interior. Comparison of clustering of vacancies

  9. Defects in nematic membranes can buckle into pseudospheres

    E-Print Network [OSTI]

    John R. Frank; Mehran Kardar

    2007-10-31T23:59:59.000Z

    A nematic membrane is a sheet with embedded orientational order, which can occur in biological cells, liquid crystal films, manufactured materials, and other soft matter systems. By formulating the free energy of nematic films using tensor contractions from differential geometry, we elucidate the elastic terms allowed by symmetry, and indicate differences from hexatic membranes. We find that topological defects in the orientation field can cause the membrane to buckle over a size set by the competition between surface tension and in-plane elasticity. In the absence of bending rigidity the resulting shape is universal, known as a parabolic pseudosphere or a revolved tractrix. Bending costs oppose such buckling and modify the shape in a predictable manner. In particular, the anisotropic rigidities of nematic membranes lead to different shapes for aster and vortex defects, in principle enabling measurement of couplings specific to nematic membranes.

  10. Doping-assisted defect control in compound semiconductors

    SciTech Connect (OSTI)

    Specht, Petra; Weber, Eicke R.; Weatherford, Todd Russell

    2006-07-11T23:59:59.000Z

    The present invention relates to the production of thin film epilayers of III–V and other compounds with acceptor doping wherein the acceptor thermally stabilizes the epilayer, stabilize the naturally incorporated native defect population and therewith maintain the epilayer's beneficial properties upon annealing among other advantageous effects. In particular, balanced doping in which the acceptor concentration is similar to (but does not exceed) the antisite defects in the as-grown material is shown to be particularly advantageous in providing thermal stability, high resistivity and ultrashort trapping times. In particular, MBE growth of LT-GaAs epilayers with balanced Be doping is described in detail. The growth conditions greatly enhance the materials reproducibility (that is, the yield in processed devices). Such growth techniques can be transferred to other III–V materials if the growth conditions are accurately reproduced. Materials produced herein also demonstrate advantages in reproducibility, reliability and radiation hardening.

  11. Adsorption of self-avoiding walks at a defect

    E-Print Network [OSTI]

    Nicholas R. Beaton

    2014-09-01T23:59:59.000Z

    We consider the model of self-avoiding walks on the $d$-dimensional hypercubic lattice interacting with a $d^*$-dimensional defect, where $1\\leq d^*defect. When $d=3$ and $d^*=1$ or $2$, this can be seen as a model of long linear polymers in a good solvent, interacting with a linear filament or the interface of two liquids of different density. For all combinations of dimensions, there is a critical value $a_{\\rm c}$ which separates the desorbed and adsorbed phases of the model. We prove that in all cases $a_{\\rm c}=1$, confirming conjectures by a number of authors.

  12. CASTING DEFECT MODELING IN AN INTEGRATED COMPUTATIONAL MATERIALS ENGINEERING APPROACH

    SciTech Connect (OSTI)

    Sabau, Adrian S [ORNL

    2015-01-01T23:59:59.000Z

    To accelerate the introduction of new cast alloys, the simultaneous modeling and simulation of multiphysical phenomena needs to be considered in the design and optimization of mechanical properties of cast components. The required models related to casting defects, such as microporosity and hot tears, are reviewed. Three aluminum alloys are considered A356, 356 and 319. The data on calculated solidification shrinkage is presented and its effects on microporosity levels discussed. Examples are given for predicting microporosity defects and microstructure distribution for a plate casting. Models to predict fatigue life and yield stress are briefly highlighted here for the sake of completion and to illustrate how the length scales of the microstructure features as well as porosity defects are taken into account for modeling the mechanical properties. Thus, the data on casting defects, including microstructure features, is crucial for evaluating the final performance-related properties of the component. ACKNOWLEDGEMENTS This work was performed under a Cooperative Research and Development Agreement (CRADA) with the Nemak Inc., and Chrysler Co. for the project "High Performance Cast Aluminum Alloys for Next Generation Passenger Vehicle Engines. The author would also like to thank Amit Shyam for reviewing the paper and Andres Rodriguez of Nemak Inc. Research sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, as part of the Propulsion Materials Program under contract DE-AC05-00OR22725 with UT-Battelle, LLC. Part of this research was conducted through the Oak Ridge National Laboratory's High Temperature Materials Laboratory User Program, which is sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Program.

  13. Plasma-based localized defect for switchable coupling applications

    SciTech Connect (OSTI)

    Varault, Stefan [ONERA/DEMR, 2, Avenue Edouard Belin, BP4025, 31055 Toulouse Cedex (France); LAboratoire PLAsma et Conversion d'Energie (LAPLACE), UPS, CNRS, 118 Route de Narbonne, F-31062 Toulouse Cedex 9 (France); Gabard, Benjamin [STAE, 4, rue Emile Monso, BP84234, 31030 Toulouse, Cedex 4 (France); Sokoloff, Jerome [LAboratoire PLAsma et Conversion d'Energie (LAPLACE), UPS, CNRS, 118 Route de Narbonne, F-31062 Toulouse Cedex 9 (France); Bolioli, Sylvain [ONERA/DEMR, 2, Avenue Edouard Belin, BP4025, 31055 Toulouse Cedex (France)

    2011-03-28T23:59:59.000Z

    We report in this paper experimental measurements in order to validate the concept of switchable electromagnetic band gap filters based on plasma capillaries in the microwave regime. The plasma tube is embedded inside the structure to create a bistable (plasma on or off) punctual defect. We first investigate two kinds of discharge tubes: Ar-Hg and pure Ne, which we then use to experimentally achieve plasma-based reconfigurable applications, namely, a two-port coupler and a two-port demultiplexer.

  14. Improving Cooling performance of the mechanical resonator with the two-level-system defects

    E-Print Network [OSTI]

    Tian Chen; Xiang-Bin Wang

    2014-06-03T23:59:59.000Z

    We study cooling performance of a realistic mechanical resonator containing defects. The normal cooling method through an optomechanical system does not work efficiently due to those defects. We show by employing periodical $\\sigma_z$ pulses, we can eliminate the interaction between defects and their surrounded heat baths up to the first order of time. Compared with the cooling performance of no $\\sigma_z$ pulses case, much better cooling results are obtained. Moreover, this pulse sequence has an ability to improve the cooling performance of the resonator with different defects energy gaps and different defects damping rates.

  15. Ab initio studies of niobium defects in uranium

    SciTech Connect (OSTI)

    Xiang, S; Huang, H; Hsiung, L

    2007-06-01T23:59:59.000Z

    Uranium (U), with the addition of small amount of niobium (Nb), is stainless. The Nb is fully miscible with the high temperature phase of U and tends to segregate upon cooling below 647 C. The starting point of segregation is the configuration of Nb substitutional or interstitial defects. Using density-functional-theory based ab initio calculations, the authors find that the formation energy of a single vacancy is 1.08 eV, that of Nb substitution is 0.59 eV, that of Nb interstitial at octahedral site is 1.58 eV, and that of Nb interstitial at tetrahedral site is 2.35 eV; all with reference to a reservoir of {gamma} phase U and pure Nb. The formation energy of Nb defects correlates with the local perturbation of electron distribution; higher formation energy to larger perturbation. Based on this study, Nb atoms thermodynamically prefer to occupy substitutional sites in {gamma} phase U, and they prefer to be in individual substitutional defects than clusters.

  16. Light defection due to a charged, rotating body

    E-Print Network [OSTI]

    Sarani Chakraborty; A. K. Sen

    2014-06-05T23:59:59.000Z

    According to GTR and subsequent developments in the field, it is known that there are three factors namely mass, rotation and charge that can influence the space-time geometry. Accordingly, we discuss the effect of space-time geometry of a charged, rotating body on the motion of the light ray. We obtained the expression for equatorial defection of light due to such a body up to fourth order term. In our expression for defection angle it is clear that charge can influence the path of light ray. We used the null geodesic approach of light ray for our calculation. If we set the charge to zero our expression of bending angle gets reduced to the Kerr equatorial bending angle.If we set rotation to zero our expression reduces to Resinner-Nordstr$\\ddot{o}$m defection angle and if we set both charge and rotation to zero our expression reduces to Schwarzschild bending angle. However, we get non-zero bending angle for a hypothetical massless, rotating, charged body.

  17. Nature of Radiation-Induced Defects in Quartz

    E-Print Network [OSTI]

    Wang, Bu; Pignatelli, Isabella; Sant, Gaurav N; Bauchy, Mathieu

    2015-01-01T23:59:59.000Z

    Although quartz ($\\rm \\alpha$-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage have not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics (MD) simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si--O connectivity defects, e.g., small Si--O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on $E^{\\prime}$ centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependenc...

  18. Enhanced optical power of GaN-based light-emitting diode with compound photonic crystals by multiple-exposure nanosphere-lens lithography

    SciTech Connect (OSTI)

    Zhang, Yonghui; Wei, Tongbo, E-mail: tbwei@semi.ac.cn; Xiong, Zhuo; Shang, Liang; Tian, Yingdong; Zhao, Yun; Zhou, Pengyu; Wang, Junxi; Li, Jinmin [Semiconductor Lighting Technology Research and Development Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2014-07-07T23:59:59.000Z

    The light-emitting diodes (LEDs) with single, twin, triple, and quadruple photonic crystals (PCs) on p-GaN are fabricated by multiple-exposure nanosphere-lens lithography (MENLL) process utilizing the focusing behavior of polystyrene spheres. Such a technique is easy and economical for use in fabricating compound nano-patterns. The optimized tilted angle is decided to be 26.6° through mathematic calculation to try to avoid the overlay of patterns. The results of scanning electron microscopy and simulations reveal that the pattern produced by MENLL is a combination of multiple ovals. Compared to planar-LED, the light output power of LEDs with single, twin, triple, and quadruple PCs is increased by 14.78%, 36.03%, 53.68%, and 44.85% under a drive current 350?mA, respectively. Furthermore, all PC-structures result in no degradation of the electrical properties. The stimulated results indicate that the highest light extraction efficiency of LED with the clover-shape triple PC is due to the largest scattering effect on propagation of light from GaN into air.

  19. Architectures built using bottom-up self-assembly of nanoelectronic devices will need to tolerate defect rates that

    E-Print Network [OSTI]

    Sorin, Daniel J.

    in the lithography process, the high energy associated with shorter wavelengths and the accuracy needed to fabricate1 Abstract Architectures built using bottom-up self-assembly of nanoelectronic devices will need isolation. Simulations show that, for a fail-stop model of node failure, the broadcast connects all nodes

  20. Architectures built using bottom-up self-assembly of nanoelectronic devices will need to tolerate defect rates that

    E-Print Network [OSTI]

    Dwyer, Chris

    in the lithography process, the high energy associated with shorter wavelengths and the accuracy needed to fabricateAbstract Architectures built using bottom-up self-assembly of nanoelectronic devices will need isolation. Simulations show that, for a fail-stop model of node failure, the broadcast connects all nodes

  1. Blade reliability collaborative : collection of defect, damage and repair data.

    SciTech Connect (OSTI)

    Ashwill, Thomas D.; Ogilvie, Alistair B.; Paquette, Joshua A.

    2013-04-01T23:59:59.000Z

    The Blade Reliability Collaborative (BRC) was started by the Wind Energy Technologies Department of Sandia National Laboratories and DOE in 2010 with the goal of gaining insight into planned and unplanned O&M issues associated with wind turbine blades. A significant part of BRC is the Blade Defect, Damage and Repair Survey task, which will gather data from blade manufacturers, service companies, operators and prior studies to determine details about the largest sources of blade unreliability. This report summarizes the initial findings from this work.

  2. Preshot Predictions for Defect Induced Mix (DIME) Capsules

    SciTech Connect (OSTI)

    Bradley, Paul A. [Los Alamos National Laboratory; Krasheninnikova, Natalia S. [Los Alamos National Laboratory; Tregillis, Ian L. [Los Alamos National Laboratory; Schmitt, Mark J. [Los Alamos National Laboratory

    2012-07-31T23:59:59.000Z

    In this memo, we evaluate the most probable yield and other results for the Defect Induced Mix (DIME-12A) Polar Direct Drive (PDD) capsule-only shots. We evaluate the expected yield, bang time, burn averaged ion temperature, and the average electron temperature of the Ge line-emitting region. We also include synthetic images of the capsule backlit by Cu K-{alpha} emission (8.39 keV) and core self-emission synthetic images. This memo is a companion to the maximum credible yield memo (LA-UR-12-00287) published earlier.

  3. Thermal imaging analysis of material structures and defects.

    SciTech Connect (OSTI)

    Sun, J. G.; Nuclear Engineering Division

    2008-01-01T23:59:59.000Z

    A numerical one-dimensional (1D) heat-transfer model was developed to simulate the surface temperature response under one-sided pulsed thermal imaging for plate samples with internal material variations including different optical and thermal properties, multilayer structures, and defect distributions (delaminations). The simulation results showed the complexity and subtle differences of the thermal imaging response to the material variations. With further development in data processing technologies, it is expected that thermal imaging may be used to detect and predict these material property variations.

  4. Structures And Magnetization Of Defect-Associated Sites In Silicon

    SciTech Connect (OSTI)

    Chow, L.; Gonzalez-Pons, J. C.; Barco, E. del [Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States); Vanfleet, R. [Department of Physics, Brigham Young University, Provo, UT 84602 (United States); Misiuk, A. [Institute of Electron Technology (ITE), al. Lotnikow 32/46, Warsaw 02-668 Poland (Poland); Barcz, A. [Institute of Electron Technology (ITE), al. Lotnikow 32/46, Warsaw 02-668 Poland (Poland); Polish Academy of Science, Institute of Physics, al Lotnikow 32/46, Warsaw 02-668 Poland (Poland); Choi, E. S. [NHMFL, Florida State University, Tallahassee, FL 32310-3706 (United States); Chai, G. [Apollo Technologies, Inc. 205 Waymont Court, Suite 111, Lake Mary, FL 32746 (United States)

    2008-04-24T23:59:59.000Z

    To better understand the mechanism of the reported 'quasi-ferromagnetism' observed in Si ions self-implanted or irradiated silicon, we carry out high resolution transmission electron microscopy (HRTEM), magnetization measurements using superconducting quantum interference device (SQUID) magnetometer, and ferromagnetic resonance (FMR) measurements of the magnetic interaction of the defect-associated sites in silicon damaged by silicon self-implantation or energetic particle beams. The SQUID measurements showed that the silicon self-implanted sample has paramagnetic ordering. FMR measurements indicated the He{sup ++} irradiated sample has a ferromagnetic interaction and yields a Lande g-factor of 2.35.

  5. Sandia Energy - Research Challenge 4: Defect-Carrier Interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear PressLaboratory FellowsPolariton4: Defect-Carrier

  6. Sandia National Laboratories: MASK

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the extent to which control strategies can increase the power produced by resonant wave-energy converter (WEC) devices. Many theoretical studies have shown a promise that...

  7. Simulation and analysis on ultrasonic testing for the cement grouting defects of the corrugated pipe

    SciTech Connect (OSTI)

    Qingbang, Han; Ling, Chen; Changping, Zhu [Changzhou Key Laboratory of Sensor Networks and Environmental Sensing, College of IOT, Hohai University Changzhou, Jiangsu, 213022 (China)

    2014-02-18T23:59:59.000Z

    The defects exist in the cement grouting process of prestressed corrugated pipe may directly impair the bridge safety. In this paper, sound fields propagation in concrete structures with corrugated pipes and the influence of various different defects are simulated and analyzed using finite element method. The simulation results demonstrate a much complex propagation characteristic due to multiple reflection, refraction and scattering, where the scattering signals caused by metal are very strong, while the signals scattered by an air bubble are weaker. The influence of defect both in time and frequency domain are found through deconvolution treatment. In the time domain, the deconvolution signals correspond to larger defect display a larger head wave amplitude and shorter arrive time than those of smaller defects; in the frequency domain, larger defect also shows a stronger amplitude, lower center frequency and lower cutoff frequency.

  8. 10^{-7} contrast ratio at 4.5Lambda/D: New results obtained in laboratory experiments using nano-fabricated coronagraph and multi-Gaussian shaped pupil masks

    E-Print Network [OSTI]

    Abhijit Chakraborty; Laird A. Thompson; Mike Rogosky

    2005-04-05T23:59:59.000Z

    We present here new experimental results on high contrast imaging of 10^{-7} at 4.5Lambda/D (Lambda = 0.820 microns) by combining a circular focal plane mask (coronagraph) of 2.5Lambda/D diameter and a multi-Gaussian pupil plane mask. Both the masks were fabricated on very high surface quality (Lambda/30) BK7 optical substrates using nano-fabrication techniques of photolithography and metal lift-off. This process ensured that the shaped masks have a useable edge roughness better than Lambda/4 (rms error better than 0.2 microns), a specification that is necessary to realize the predicted theoretical limits of any mask design. Though a theoretical model predicts a contrast level of 10^{-12}, the background noise of the observed images was speckle dominated which reduced the contrast level to 4x10^{-7} at 4.5Lambda/D. The optical setup was built on the University of Illinois Seeing Improvement System (UnISIS) optics table which is at the Coude focus of the 2.5-m telescope of the Mt. Wilson Observatory. We used a 0.820 micron laser source coupled with a 5 micron single-mode fiber to simulate an artificial star on the optical test bench of UnISIS.

  9. Eddy Current Signature Classification of Steam Generator Tube Defects Using A Learning Vector Quantization Neural Network

    SciTech Connect (OSTI)

    Gabe V. Garcia

    2005-01-03T23:59:59.000Z

    A major cause of failure in nuclear steam generators is degradation of their tubes. Although seven primary defect categories exist, one of the principal causes of tube failure is intergranular attack/stress corrosion cracking (IGA/SCC). This type of defect usually begins on the secondary side surface of the tubes and propagates both inwards and laterally. In many cases this defect is found at or near the tube support plates.

  10. Spatial correlation between chemical and topological defects in vitreous silica: UV-resonance Raman study

    SciTech Connect (OSTI)

    Saito, M., E-mail: makina.saito@elettra.eu; D’Amico, F.; Bencivenga, F.; Cucini, R.; Gessini, A.; Principi, E.; Masciovecchio, C. [Elettra-Sincrotrone Trieste, S. S. 14 Km 163.5, I-34149 Trieste (Italy)

    2014-06-28T23:59:59.000Z

    A spatial correlation between chemical and topological defects in the tetrahedron network in vitreous silica produced by a fusion process of natural quartz crystals was found by synchrotron-based UV resonance Raman experiments. Furthermore, a quantitative correlation between these defects was obtained by comparing visible Raman and UV absorption spectra. These results indicate that in vitreous silica produced by the fusion process the topological defects disturb the surrounding tetrahedral silica network and induce further disorder regions with sub nanometric sizes.

  11. Multiple stalk formation as a pathway of defect-induced membrane fusion

    E-Print Network [OSTI]

    D. B. Lukatsky; Daan Frenkel

    2004-03-29T23:59:59.000Z

    We propose that the first stage of membrane fusion need not be the formation of a single stalk. Instead, we consider a scenario for defect-induced membrane fusion that proceeds cooperatively via multiple stalk formation. The defects (stalks or pores) attract each other via membrane-mediated capillary interactions that result in a condensation transition of the defects. The resulting dense phase of stalks corresponds to the so-called fusion intermediate.

  12. Gauge turbulence, topological defect dynamics, and condensation in Higgs models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gasenzer, Thomas [Universitat Heidelberg, Institut fur Theoretische Physik, Heidelberg (Germany); GSI, ExtreMe Matter Institute EMMI, Darmstadt (Germany); McLerran, Larry [Brookhaven National Laboratory, Physics Department, RIKEN BNL Research Center Upton NY (United States); China Central Normal University, Physics Department, Wuhan (China); Pawlowski, Jan M [Universitat Heidelberg, Institut fur Theoretische Physik, Heidelberg (Germany); GSI, ExtreMe Matter Institute EMMI, Darmstadt (Germany); Sexty, Denes [Universitat Heidelberg, Institut fur Theoretische Physik, Heidelberg (Germany); GSI, ExtreMe Matter Institute EMMI, Darmstadt (Germany)

    2014-10-01T23:59:59.000Z

    The real-time dynamics of topological defects and turbulent configurations of gauge fields for electric and magnetic confinement are studied numerically within a 2+1D Abelian Higgs model. It is shown that confinement is appearing in such systems equilibrating after a strong initial quench such as the overpopulation of the infrared modes. While the final equilibrium state does not support confinement, metastable vortex defect configurations appearing in the gauge field are found to be closely related to the appearance of physically observable confined electric and magnetic charges. These phenomena are seen to be intimately related to the approach of a non-thermal fixed point of the far-from-equilibrium dynamical evolution, signaled by universal scaling in the gauge-invariant correlation function of the Higgs field. Even when the parameters of the Higgs action do not support condensate formation in the vacuum, during this approach, transient Higgs condensation is observed. We discuss implications of these results for the far-from-equilibrium dynamics of Yang–Mills fields and potential mechanisms of how confinement and condensation in non-Abelian gauge fields can be understood in terms of the dynamics of Higgs models. These suggest that there is an interesting new class of dynamics of strong coherent turbulent gauge fields with condensates.

  13. Subsurface Defect Detection in Metals with Pulsed Eddy Current

    SciTech Connect (OSTI)

    Plotnikov, Yuri A. [GE Global Research Center, One Research Circle, Niskayuna, NY 12309-1135 (United States); Bantz, Walter J. [GE Aircraft Engines M and QTD, 10270 St. Rita Lane, Cincinnati, OH 45215 (United States)

    2005-04-09T23:59:59.000Z

    The eddy current (EC) method is traditionally used for open surface crack detection in metallic components. Subsurface voids in bulk metals can also be detected by the eddy current devices. Taking into consideration the skin effect in conductive materials, a lower frequency of electromagnetic excitation is used for a deeper penetration. A set of special specimens was designed and fabricated to investigate sensitivity to subsurface voids. Typically, flat bottom holes (FBHs) are used for subsurface defect simulation. This approach is not very representative of real defects for eddy current inspection because the FBH depth extends to the bottom of the specimen. Two-layer specimens with finite depth FBHs were fabricated and scanned with conventional EC of variable frequency. Sensitivity and spatial resolution of EC diminish with flaw depth. The pulsed EC approach was applied for flaw detection at variable distance under the surface. The transient response from multi-layer model was derived and compared to experiments. The multi-frequency nature of pulsed excitation provides effective coverage of a thick layer of material in one pass. Challenging aspects of subsurface flaw detection and visualization using the EC technique are discussed.

  14. Gauge turbulence, topological defect dynamics, and condensation in Higgs models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gasenzer, Thomas; McLerran, Larry; Pawlowski, Jan M.; Sexty, Dénes

    2014-10-01T23:59:59.000Z

    The real-time dynamics of topological defects and turbulent configurations of gauge fields for electric and magnetic confinement are studied numerically within a 2+1D Abelian Higgs model. It is shown that confinement is appearing in such systems equilibrating after a strong initial quench such as the overpopulation of the infrared modes. While the final equilibrium state does not support confinement, metastable vortex defect configurations appearing in the gauge field are found to be closely related to the appearance of physically observable confined electric and magnetic charges. These phenomena are seen to be intimately related to the approach of a non-thermal fixedmore »point of the far-from-equilibrium dynamical evolution, signaled by universal scaling in the gauge-invariant correlation function of the Higgs field. Even when the parameters of the Higgs action do not support condensate formation in the vacuum, during this approach, transient Higgs condensation is observed. We discuss implications of these results for the far-from-equilibrium dynamics of Yang–Mills fields and potential mechanisms of how confinement and condensation in non-Abelian gauge fields can be understood in terms of the dynamics of Higgs models. These suggest that there is an interesting new class of dynamics of strong coherent turbulent gauge fields with condensates.« less

  15. Nematic ordering of topological defects in active liquid crystals

    E-Print Network [OSTI]

    Anand U. Oza; Jörn Dunkel

    2015-07-15T23:59:59.000Z

    Identifying the ordering principles of intracellular matter is key to understanding the physics of microbiological systems. Recent experiments show that ATP-driven microtubule-kinesin bundles can form non-equilibrium networks of liquid-crystalline order when trapped in an oil-water interface near a solid boundary. At high densities, the bundles realize a 2D active nematic phase characterized by spontaneous creation and annihilation of topological defects, reminiscent of particle-pair production processes in quantum systems. This remarkable discovery sparked considerable theoretical interest, yet a satisfactory mathematical description has remained elusive, primarily for the following two reasons. First, prevailing multi-component theories feature a large number of unknown parameters that make quantitative comparison with experiment infeasible. Second, the currently favored hydrodynamic models assume divergence-free 2D interfacial flow, thereby promoting turbulent pattern formation through upward cascades. Such cascades are unlikely to occur in experiments, where interface and bulk fluid can continuously exchange matter. Here, we propose a compact alternative continuum theory for dense active liquid crystals by merging ideas from the Landau-de Gennes and Swift-Hohenberg theories. The resulting fourth-order model agrees quantitatively with experimental data, correctly predicts a regime of long-range nematic alignment of defects, and manifests an analogy with a generalized Gross-Pitaevskii quantum theory. Generally, our results suggest that universal ordering principles may govern a wide range of active materials.

  16. Defect Prevention and Detection in Software for Automated Test Equipment

    SciTech Connect (OSTI)

    E. Bean

    2006-11-30T23:59:59.000Z

    Software for automated test equipment can be tedious and monotonous making it just as error-prone as other software. Active defect prevention and detection are also important for test applications. Incomplete or unclear requirements, a cryptic syntax used for some test applications—especially script-based test sets, variability in syntax or structure, and changing requirements are among the problems encountered in one tester. Such problems are common to all software but can be particularly problematic in test equipment software intended to test another product. Each of these issues increases the probability of error injection during test application development. This report describes a test application development tool designed to address these issues and others for a particular piece of test equipment. By addressing these problems in the development environment, the tool has powerful built-in defect prevention and detection capabilities. Regular expressions are widely used in the development tool as a means of formally defining test equipment requirements for the test application and verifying conformance to those requirements. A novel means of using regular expressions to perform range checking was developed. A reduction in rework and increased productivity are the results. These capabilities are described along with lessons learned and their applicability to other test equipment software. The test application development tool, or “application builder”, is known as the PT3800 AM Creation, Revision and Archiving Tool (PACRAT).

  17. Defect induced plasticity and failure mechanism of boron nitride nanotubes under tension

    SciTech Connect (OSTI)

    Anoop Krishnan, N. M., E-mail: anoopnm@civil.iisc.ernet.in; Ghosh, Debraj [Indian Institute of Science, Bangalore 560012 (India)

    2014-07-28T23:59:59.000Z

    The effects of Stone-Wales (SW) and vacancy defects on the failure behavior of boron nitride nanotubes (BNNTs) under tension are investigated using molecular dynamics simulations. The Tersoff-Brenner potential is used to model the atomic interaction and the temperature is maintained close to 300?K. The effect of a SW defect is studied by determining the failure strength and failure mechanism of nanotubes with different radii. In the case of a vacancy defect, the effect of an N-vacancy and a B-vacancy is studied separately. Nanotubes with different chiralities but similar diameter is considered first to evaluate the chirality dependence. The variation of failure strength with the radius is then studied by considering nanotubes of different diameters but same chirality. It is observed that the armchair BNNTs are extremely sensitive to defects, whereas the zigzag configurations are the least sensitive. In the case of pristine BNNTs, both armchair and zigzag nanotubes undergo brittle failure, whereas in the case of defective BNNTs, only the zigzag ones undergo brittle failure. An interesting defect induced plastic behavior is observed in defective armchair BNNTs. For this nanotube, the presence of a defect triggers mechanical relaxation by bond breaking along the closest zigzag helical path, with the defect as the nucleus. This mechanism results in a plastic failure.

  18. 2012 DEFECTS IN SEMICONDUCTORS GORDON RESEARCH CONFERENCE, AUGUST 12-17, 2012

    SciTech Connect (OSTI)

    GLASER, EVAN

    2012-08-17T23:59:59.000Z

    The meeting shall strive to develop and further the fundamental understanding of defects and their roles in the structural, electronic, optical, and magnetic properties of bulk, thin film, and nanoscale semiconductors and device structures. Point and extended defects will be addressed in a broad range of electronic materials of particular current interest, including wide bandgap semiconductors, metal-oxides, carbon-based semiconductors (e.g., diamond, graphene, etc.), organic semiconductors, photovoltaic/solar cell materials, and others of similar interest. This interest includes novel defect detection/imaging techniques and advanced defect computational methods.

  19. HIGH QUALITY InGaN FOR PHOTOVOLTAIC APPLICATIONS: TYPE AND SPATIAL DISTRIBUTION OF CRYSTALLINE DEFECTS

    E-Print Network [OSTI]

    Honsberg, Christiana

    of defects act as recombination channels and lower the short-circuit current, as well as tend to pin the open-circuit

  20. Interstitial defects in silicon from 1{endash}5 keV Si{sup +} ion implantation

    SciTech Connect (OSTI)

    Agarwal, A.; Haynes, T.E. [Oak Ridge National Laboratory, MS-6048, Oak Ridge, Tennessee 37831 (United States)] [Oak Ridge National Laboratory, MS-6048, Oak Ridge, Tennessee 37831 (United States); Eaglesham, D.J.; Gossmann, H.; Jacobson, D.C.; Poate, J.M. [Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States)] [Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Erokhin, Y.E. [Eaton Corporation, 108 Cherry Hill Drive, Beverly, Massachusetts 01915 (United States)] [Eaton Corporation, 108 Cherry Hill Drive, Beverly, Massachusetts 01915 (United States)

    1997-06-01T23:59:59.000Z

    Extended defects from 5-, 2-, and 1-keV Si{sup +} ion implantation are investigated by transmission electron microscopy using implantation doses of 1 and 3{times}10{sup 14}cm{sup {minus}2} and annealing temperatures from 750 to 900{degree}C. Despite the proximity of the surface, {l_brace}311{r_brace}-type defects are observed even for 1 keV. Samples with a peak concentration of excess interstitials exceeding {approximately}1{percent} of the atomic density also contain some {l_brace}311{r_brace} defects which are corrugated across their width. These so-called zig-zag {l_brace}311{r_brace} defects are more stable than the ordinary {l_brace}311{r_brace} defects, having a dissolution rate at 750{degree}C which is ten times smaller. Due to their enhanced stability, the zig-zag {l_brace}311{r_brace} defects grow to lengths that are many times longer than their distance from the surface. It is proposed that zig-zag {l_brace}311{r_brace} defects form during the early stages of annealing by coalescence the high volume density of {l_brace}311{r_brace} defects confined within a very narrow implanted layer. These findings indicate that defect formation and dissolution will continue to control the interstitial supersaturation from ion implantation down to very low energies. {copyright} {ital 1997 American Institute of Physics.}

  1. Proceedings of NAMRI/SME, Vol. 41, 2013 Removal Mechanism and Defect Characterization for Glass-

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    Proceedings of NAMRI/SME, Vol. 41, 2013 Removal Mechanism and Defect Characterization for Glass of NAMRI/SME, Vol. 41, 2013 f

  2. Electrodes mitigating effects of defects in organic electronic devices

    DOE Patents [OSTI]

    Heller, Christian Maria Anton (Albany, NY)

    2008-05-06T23:59:59.000Z

    A compound electrode for organic electronic devices comprises a thin first layer of a first electrically conducting material and a second electrically conducting material disposed on the first layer. In one embodiment, the second electrically conducting material is formed into a plurality of elongated members. In another embodiment, the second material is formed into a second layer. The elongated members or the second layer has a thickness greater than that of the first layer. The second layer is separated from the first layer by a conducting material having conductivity less than at least the material of the first layer. The compound electrode is capable of mitigating adverse effects of defects, such as short circuits, in the construction of the organic electronic devices, and can be included in light-emitting or photovoltaic devices.

  3. Defect localization, characterization and reliability assessment in emerging photovoltaic devices.

    SciTech Connect (OSTI)

    Yang, Benjamin Bing-Yeh; Cruz-Campa, Jose Luis; Haase, Gad S.; Tangyunyong, Paiboon; Cole, Edward Isaac,; Okandan, Murat; Nielson, Gregory N.

    2014-04-01T23:59:59.000Z

    Microsystems-enabled photovoltaics (MEPV) can potentially meet increasing demands for light-weight, portable, photovoltaic solutions with high power density and efficiency. The study in this report examines failure analysis techniques to perform defect localization and evaluate MEPV modules. CMOS failure analysis techniques, including electroluminescence, light-induced voltage alteration, thermally-induced voltage alteration, optical beam induced current, and Seabeck effect imaging were successfully adapted to characterize MEPV modules. The relative advantages of each approach are reported. In addition, the effects of exposure to reverse bias and light stress are explored. MEPV was found to have good resistance to both kinds of stressors. The results form a basis for further development of failure analysis techniques for MEPVs of different materials systems or multijunction MEPVs. The incorporation of additional stress factors could be used to develop a reliability model to generate lifetime predictions for MEPVs as well as uncover opportunities for future design improvements.

  4. Periodic Schrödinger operators with local defects and spectral pollution

    E-Print Network [OSTI]

    Eric Cancčs; Virginie Ehrlacher; Yvon Maday

    2011-11-16T23:59:59.000Z

    This article deals with the numerical calculation of eigenvalues of perturbed periodic Schr\\"odinger operators located in spectral gaps. Such operators are encountered in the modeling of the electronic structure of crystals with local defects, and of photonic crystals. The usual finite element Galerkin approximation is known to give rise to spectral pollution. In this article, we give a precise description of the corresponding spurious states. We then prove that the supercell model does not produce spectral pollution. Lastly, we extend results by Lewin and S\\'er\\'e on some no-pollution criteria. In particular, we prove that using approximate spectral projectors enables one to eliminate spectral pollution in a given spectral gap of the reference periodic Sch\\"odinger operator.

  5. Directed polymers in a random environment with a defect line

    E-Print Network [OSTI]

    Kenneth S. Alexander; Gökhan Y?ld?r?m

    2015-01-21T23:59:59.000Z

    We study the depinning transition of the $1+1$ dimensional directed polymer in a random environment with a defect line. The random environment consists of i.i.d. potential values assigned to each site of $\\mathbb{Z}^2$; sites on the positive axis have the potential enhanced by a deterministic value $u$. We show that for small inverse temperature $\\beta$ the quenched and annealed free energies differ significantly at most in a small neighborhood (of size of order $\\beta$) of the annealed critical point $u_c^a=0$. For the case $u=0$, we show that the difference between quenched and annealed free energies is of order $\\beta^4$ as $\\beta\\to 0$, assuming only finiteness of exponential moments of the potential values, improving existing results which required stronger assumptions.

  6. Defects and diffusion in MeV implanted silicon

    SciTech Connect (OSTI)

    Venezia, V. C.; Haynes, T. E.; Agarwal, Aditya; Gossmann, H.-J.; Pelaz, L.; Jacobson, D. C.; Eaglesham, D. J.; Duggan, J. L. [Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Solid State Division, Oak Ridge National Laboratory, MS-6048, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States); Semiconductor Equipment Operations, Eaton Corporation, 55 Cherry Hill Drive, Beverly, Massachusetts 01915 (United States); Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Department of Physics, University of North Texas, Denton, Texas 76201 (United States)

    1999-06-10T23:59:59.000Z

    In this work we demonstrate that the defects that are created by 2-MeV Si ions can interact with dopant atoms both during implantation and during post-implant annealing. We show that the interstitials and vacancies created during MeV Si implantation result in a radiation enhanced diffusion of B and Sb markers, respectively, when the temperature of implantation is above the threshold temperature for formation of mobile dopant complexes. With the use of these dopant markers we also demonstrate that a vacancy-rich near surface region results during post-implant annealing of MeV implanted silicon. The depth distribution and the thermal evolution of clustered vacancies was measured by a Au labeling technique.

  7. Ion beam collimating grid to reduce added defects

    DOE Patents [OSTI]

    Lindquist, Walter B. (Oakland, CA); Kearney, Patrick A. (Livermore, CA)

    2003-01-01T23:59:59.000Z

    A collimating grid for an ion source located after the exit grid. The collimating grid collimates the ion beamlets and disallows beam spread and limits the beam divergence during transients and steady state operation. The additional exit or collimating grid prevents beam divergence during turn-on and turn-off and prevents ions from hitting the periphery of the target where there is re-deposited material or from missing the target and hitting the wall of the vessel where there is deposited material, thereby preventing defects from being deposited on a substrate to be coated. Thus, the addition of a collimating grid to an ion source ensures that the ion beam will hit and be confined to a specific target area.

  8. Intracardiac Echocardiography Evaluation in Secundum Atrial Septal Defect Transcatheter Closure

    SciTech Connect (OSTI)

    Zanchetta, Mario; Pedon, Luigi; Rigatelli, Gianluca; Carrozza, Antonio; Zennaro, Marco; Di Martino, Roberta [Department of Cardiovascular Disease, Cittadella General Hospital, Cittadella, Padua (Italy); Onorato, Eustaquio [Operative Unit ofCardiology, Clinica S. Rocco, Ome, Brescia (Italy); Maiolino, Pietro [Department of Cardiovascular Disease, Cittadella General Hospital, Cittadella, Padua (Italy)

    2003-02-15T23:59:59.000Z

    Purpose: This study was designed to assess the balloon sizing maneuvers and deployment of an Amplatzer Septal Occluder (ASO). In addition, intraprocedural balloon sizing was compared with off-line intracardiac echocardiographic measurements. Methods: The intracardiac echocardiography (ICE) measurements were: maximum transverse and longitudinal atrial septal defect (ASD) diameters in the aortic valve and four-chamber planes;area of the ASD and its equivalent circle diameter. Thirteen consecutive patients underwent transcatheter implantation of an ASO device using ICE guidance under local anesthesia. The device matching the balloon sizing diameter of the defect was implanted. Qualitative ICE assessment of the ASO devices implanted was performed off line. Results: The mean equivalent circle diameter predicted by ICE was 24.40 {+-} 5.61 mm and was significantly higher(p 0.027) than the ASD measured by balloonsizing (21.38 {+-} 5.28 mm). Unlike previous studies we did not find any correlation between the two measurements (correlation coefficient = 0.47). Only four of the 13 patients had optimal device positioning as shown by the qualitative ICE evaluation, whereas the remaining nine patients had inadequate device placement. This resulted in a waist diameter that was an average 26.1% undersized in seven patients and 12.7% oversized in two patients. Five of the seven patients with an undersized device had ASO-atrial septum misalignment with leftward device deviation. Conclusion: The ICE images allowed careful measurement of the dimensions of the ASD and accurately displayed the spatial relations of the ASO astride the ASD.Moreover, use of the ICE measurement led to selection of a different size of device in comparison with those of balloon sizing. The clinical benefit of this new approach needs to be rigorously tested.

  9. Yield improvement and defect reduction in steel casting

    SciTech Connect (OSTI)

    Kent Carlson

    2004-03-16T23:59:59.000Z

    This research project investigated yield improvement and defect reduction techniques in steel casting. Research and technology development was performed in the following three specific areas: (1) Feeding rules for high alloy steel castings; (2) Unconventional yield improvement and defect reduction techniques--(a) Riser pressurization; and (b) Filling with a tilting mold; and (3) Modeling of reoxidation inclusions during filling of steel castings. During the preparation of the proposal for this project, these areas were identified by the High Alloy Committee and Carbon and Low Alloy Committee of the Steel Founders' Society of America (SFSA) as having the highest research priority to the steel foundry industry. The research in each of the areas involved a combination of foundry experiments, modeling and simulation. Numerous SFSA member steel foundries participated in the project through casting trials and meetings. The technology resulting from this project will result in decreased scrap and rework, casting yield improvement, and higher quality steel castings produced with less iteration. This will result in considerable business benefits to steel foundries, primarily due to reduced energy and labor costs, increased capacity and productivity, reduced lead-time, and wider use and application of steel castings. As estimated using energy data provided by the DOE, the technology produced as a result of this project will result in an energy savings of 2.6 x 10{sup 12} BTU/year. This excludes the savings that were anticipated from the mold tilting research. In addition to the energy savings, and corresponding financial savings this implies, there are substantial environmental benefits as well. The results from each of the research areas listed above are summarized.

  10. 76 PostErs EMBnet.journal 19.B An ontology describing congenital heart defects data

    E-Print Network [OSTI]

    76 PostErs EMBnet.journal 19.B An ontology describing congenital heart defects data Charalampos interests: the authors have declared that no competing interests exist. Abstract Congenital heart defects (CHDs) are a group of diseases characterized by a structural anomaly of the heart that is pre- sent

  11. Towards Fault-Tolerant Digital Microfluidic Lab-on-Chip: Defects, Fault Modeling, Testing, and Reconfiguration

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    Towards Fault-Tolerant Digital Microfluidic Lab-on-Chip: Defects, Fault Modeling, Testing, NC 27708, USA Abstract Dependability is an important attribute for microfluidic lab-on-chip devices microfluidic lab-on-chip systems. Defects are related to logical fault models that can be viewed not only

  12. Stone-Wales defects in graphene and other planar sp2 -bonded materials

    E-Print Network [OSTI]

    Alfč, Dario

    Stone-Wales defects in graphene and other planar sp2 -bonded materials Jie Ma,1,2,3 Dario Alfč,2 that the structure of the Stone-Wales SW defect in graphene is more complex than hitherto appreciated. Rather than of graphene and in so doing modify its chemical re- activity toward adsorbates, and likely impact upon its

  13. Electrochemical method for defect delineation in silicon-on-insulator wafers

    DOE Patents [OSTI]

    Guilinger, Terry R. (Albuquerque, NM); Jones, Howland D. T. (Albuquerque, NM); Kelly, Michael J. (Albuquerque, NM); Medernach, John W. (Albuquerque, NM); Stevenson, Joel O. (Albuquerque, NM); Tsao, Sylvia S. (Albuquerque, NM)

    1991-01-01T23:59:59.000Z

    An electrochemical method for defect delineation in thin-film SOI or SOS wafers in which a surface of a silicon wafer is electrically connected so as to control the voltage of the surface within a specified range, the silicon wafer is then contacted with an electrolyte, and, after removing the electrolyte, defects and metal contamination in the silicon wafer are identified.

  14. Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J. Keinonen

    E-Print Network [OSTI]

    Nordlund, Kai

    Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J-principles calculations were used in determining the binding and trapping properties of hydrogen to point defects in tungsten. Hydrogen zero-point vibrations were taken into account. It was concluded that the monovacancy can

  15. Atomistic calculations of defects in ZnGeP2 Peter Zapol and Ravindra Pandeya)

    E-Print Network [OSTI]

    Pandey, Ravi

    for native ionic defects and binding energies for some of the electronic defect complexes are calculated, Michigan Technological University, Houghton, Michigan 49931 Mel Ohmer Wright Laboratory, Wright, Technology and Medicine, South Kensington, SW7 2AY London, United Kingdom Received 5 June 1995; accepted

  16. Atomistic Modeling of Native Point Defects in Yttrium Aluminum Garnet Crystals

    E-Print Network [OSTI]

    Pandey, Ravi

    and Ravindra Pandey Department of Physics, Michigan Technological University, Houghton, Michigan 49931 Native, and dielectric constants of YAG very well. The calculated formulation energies for native defects sug- gestAtomistic Modeling of Native Point Defects in Yttrium Aluminum Garnet Crystals Maija M. Kuklja

  17. Unifying power-law behaviour, functionality and defect distribution in general software

    E-Print Network [OSTI]

    Hatton, Les

    Unifying power-law behaviour, functionality and defect distribution in general software systems Les between power-law distribution of component sizes and defect growth in maturing software systems. It was further noted that power-law distributions appear to be present in software systems from the beginning

  18. Impurity-defect interaction in polycrystalline silicon for photovoltaic applications. The role of hydrogen

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    655 Impurity-defect interaction in polycrystalline silicon for photovoltaic applications. The role of hydrogen A. Chari, P. de Mierry, A. Menikh and M. Aucouturier Laboratoire de Physique des Solides, C silicon, passivation of recombining defects by hydrogen, hydrogen-dopant interaction. A more focused

  19. Shape defect detection in ferrite cores Judit Verest'oy and Dmitry Chetverikov

    E-Print Network [OSTI]

    Chetverikov, Dmitry

    Shape defect detection in ferrite cores Judit Verest'oy and Dmitry Chetverikov Computer. The method is applied to the visual inspection and dimensional measurement of ferrite cores. An optical shape defects may deteriorate any of the dimensions. Key words: image analysis, industrial inspection, ferrite

  20. Detecting shape defects in ferrite cores \\Lambda Dmitry Chetverikov and Judit Verest'oy

    E-Print Network [OSTI]

    Chetverikov, Dmitry

    Detecting shape defects in ferrite cores \\Lambda Dmitry Chetverikov and Judit Verest'oy Computer of the objects. The method is applied to the visual inspection and dimensional measurement of ferrite cores CIPA­CT94 0153 CRASH (for CRAck and SHape defect detection in ferrite cores) which has been in progress

  1. An Approach to Detect the Origin and Distribution of Software Defects in an Evolving

    E-Print Network [OSTI]

    Ulm, Universität

    -Physical System Christian Manz1 , Michael Schulze2 , and Manfred Reichert3 1 Group Research & Advanced Engineering is necessary to ensure a reliable software defect removal. Particularly, de- tecting software defects. Keywords: Software Product Line, Evolution, Maintenance 1 Introduction Cyber-Physical Systems (CPS), like

  2. Robotic Tracking and Marking of Surface Shape Defects on Moving Automotive Panels

    E-Print Network [OSTI]

    Payeur, Pierre

    defects for quality control in the automotive industry. In order to integrate a defects detection station. INTRODUCTION Quality control in the automotive industry is essential in order to ensure that the products meet of the automotive panels, the pose and motion estimator (PME) needs to be robust to the complexity of industrial

  3. Using Explicit and Machine-Understandable Engineering Knowledge for Defect Detection in Automation Systems Engineering

    E-Print Network [OSTI]

    industrial complexes are very high. Traditional approaches for defect detection in automation systems and data models which are used within the engineering of industrial automation systems. Thus, some defects Nowadays, industrial automation systems have tendencies to become more and more complex and large

  4. The relationship between grain boundary structure, defect mobility, and grain boundary sink efficiency

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Uberuaga, Blas Pedro; Vernon, Louis J.; Martinez, Enrique; Voter, Arthur F.

    2015-03-13T23:59:59.000Z

    Nanocrystalline materials have received great attention due to their potential for improved functionality and have been proposed for extreme environments where the interfaces are expected to promote radiation tolerance. However, the precise role of the interfaces in modifying defect behavior is unclear. Using long-time simulations methods, we determine the mobility of defects and defect clusters at grain boundaries in Cu. We find that mobilities vary significantly with boundary structure and cluster size, with larger clusters exhibiting reduced mobility, and that interface sink efficiency depends on the kinetics of defects within the interface via the in-boundary annihilation rate of defects. Thus,more »sink efficiency is a strong function of defect mobility, which depends on boundary structure, a property that evolves with time. Further, defect mobility at boundaries can be slower than in the bulk, which has general implications for the properties of polycrystalline materials. Finally, we correlate defect energetics with the volumes of atomic sites at the boundary.« less

  5. Characterization of the nitrogen split interstitial defect in wurtzite aluminum nitride using density functional theory

    SciTech Connect (OSTI)

    Szállás, A., E-mail: szallas.attila@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Szász, K. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Institute of Physics, Eötvös University, Pázmány Péter sétány 1/A, H-1117 Budapest (Hungary); Trinh, X. T.; Son, N. T.; Janzén, E. [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden); Gali, A., E-mail: gali.adam@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki út 8, H-1111 Budapest (Hungary)

    2014-09-21T23:59:59.000Z

    We carried out Heyd-Scuseria-Ernzerhof hybrid density functional theory plane wave supercell calculations in wurtzite aluminum nitride in order to characterize the geometry, formation energies, transition levels, and hyperfine tensors of the nitrogen split interstitial defect. The calculated hyperfine tensors may provide useful fingerprint of this defect for electron paramagnetic resonance measurement.

  6. Electrical characterisation of defects in polycrystalline B-doped diamond films

    E-Print Network [OSTI]

    Bristol, University of

    applied to B-doped thin polycrystalline diamond films deposited on p+ -silicon by hot filament chemical]. Recently valuable information about defects in monocrystalline [3] and polycrystalline [7] diamond filmsElectrical characterisation of defects in polycrystalline B-doped diamond films O. S. Elsherif 1, a

  7. Fermi Level Control of Point Defects During Growth of Mg-Doped GaN

    E-Print Network [OSTI]

    Nabben, Reinhard

    Fermi Level Control of Point Defects During Growth of Mg-Doped GaN ZACHARY BRYAN,1,4 MARC HOFFMANN defects during metalorganic chem- ical vapor deposition (MOCVD) of Mg-doped GaN has been demonstrated of magnitude lower resistivity values compared with typical unan- nealed GaN:Mg samples. The PL spectra

  8. DuoTracker: Tool Support for Software Defect Data Collection and Analysis

    E-Print Network [OSTI]

    Dascalu, Sergiu

    evaluate their process using either the Capability Maturity Model (CMM) [3] or the ISO 9001 standards [4 software processes. Keywords--software defects; software anomalies; defect classification; PSP; CMM; IS0-9001 is then compared against the quality models of CMM or IS0 9001. There are also improvement methods such as IDEAL [5

  9. Exploring the interaction between lithium ion and defective graphene surface using dispersion corrected DFT studies

    SciTech Connect (OSTI)

    Vijayakumar, M.; Hu, Jian Z.

    2013-10-15T23:59:59.000Z

    To analyze the lithium ion interaction with realistic graphene surfaces, we carried out dispersion corrected DFT-D3 studies on graphene with common point defects and chemisorbed oxygen containing functional groups along with defect free graphene surface. Our study reveals that, the interaction between lithium ion (Li+) and graphene is mainly through the delocalized ? electron of pure graphene layer. However, the oxygen containing functional groups pose high adsorption energy for lithium ion due to the Li-O ionic bond formation. Similarly, the point defect groups interact with lithium ion through possible carbon dangling bonds and/or cation-? type interactions. Overall these defect sites render a preferential site for lithium ions compared with pure graphene layer. Based on these findings, the role of graphene surface defects in lithium battery performance were discussed.

  10. Computer code for the atomistic simulation of lattice defects and dynamics. [COMENT code

    SciTech Connect (OSTI)

    Schiffgens, J.O.; Graves, N.J.; Oster, C.A.

    1980-04-01T23:59:59.000Z

    This document has been prepared to satisfy the need for a detailed, up-to-date description of a computer code that can be used to simulate phenomena on an atomistic level. COMENT was written in FORTRAN IV and COMPASS (CDC assembly language) to solve the classical equations of motion for a large number of atoms interacting according to a given force law, and to perform the desired ancillary analysis of the resulting data. COMENT is a dual-purpose intended to describe static defect configurations as well as the detailed motion of atoms in a crystal lattice. It can be used to simulate the effect of temperature, impurities, and pre-existing defects on radiation-induced defect production mechanisms, defect migration, and defect stability.

  11. Delocalised oxygen as the origin of two-level defects in Josephson junctions

    E-Print Network [OSTI]

    Timothy C. DuBois; Manolo C. Per; Salvy P. Russo; Jared H. Cole

    2012-12-07T23:59:59.000Z

    One of the key problems facing superconducting qubits and other Josephson junction devices is the decohering effects of bi-stable material defects. Although a variety of phenomenological models exist, the true microscopic origin of these defects remains elusive. For the first time we show that these defects may arise from delocalisation of the atomic position of the oxygen in the oxide forming the Josephson junction barrier. Using a microscopic model, we compute experimentally observable parameters for phase qubits. Such defects are charge neutral but have non-zero response to both applied electric field and strain. This may explain the observed long coherence time of two-level defects in the presence of charge noise, while still coupling to the junction electric field and substrate phonons.

  12. Process for rapid detection of fratricidal defects on optics using Linescan Phase Differential Imaging

    SciTech Connect (OSTI)

    Ravizza, F L; Nostrand, M C; Kegelmeyer, L M; Hawley, R A; Johnson, M A

    2009-11-05T23:59:59.000Z

    Phase-defects on optics used in high-power lasers can cause light intensification leading to laser-induced damage of downstream optics. We introduce Linescan Phase Differential Imaging (LPDI), a large-area dark-field imaging technique able to identify phase-defects in the bulk or surface of large-aperture optics with a 67 second scan-time. Potential phase-defects in the LPDI images are indentified by an image analysis code and measured with a Phase Shifting Diffraction Interferometer (PSDI). The PSDI data is used to calculate the defects potential for downstream damage using an empirical laser-damage model that incorporates a laser propagation code. A ray tracing model of LPDI was developed to enhance our understanding of its phase-defect detection mechanism and reveal limitations.

  13. Interaction of Sn atoms with defects introduced by ion implantation in Ge substrate

    SciTech Connect (OSTI)

    Taoka, Noriyuki, E-mail: ntaoka@alice.xtal.nagoya-u.ac.jp; Fukudome, Motoshi; Takeuchi, Wakana; Arahira, Takamitsu; Sakashita, Mitsuo; Nakatsuka, Osamu; Zaima, Shigeaki [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2014-05-07T23:59:59.000Z

    The interaction of Sn atoms with defects induced by Sn implantation of Ge substrates with antimony (Sb) as an n-type dopant and the impact of H{sub 2} annealing on these defects were investigated by comparison with defects induced by Ge self-implantation. In the Ge samples implanted with either Sn or Ge, and annealed at temperatures of less than 200?°C, divacancies, Sb-vacancy complexes with single or double acceptor-like states, and defects related to Sb and interstitial Ge atoms were present. On the other hand, after annealing at 500?°C in an N{sub 2} or H{sub 2} atmosphere, defects with different structures were observed in the Sn-implanted samples by deep level transition spectroscopy. The energy levels of the defects were 0.33?eV from the conduction band minimum and 0.55?eV from the valence band maximum. From the capacitance-voltage (C-V) characteristics, interaction between Sn atoms and defects after annealing at 500?°C was observed. The effect of H{sub 2} annealing at around 200?°C was observed in the C-V characteristics, which can be attributed to hydrogen passivation, and this effect was observed in both the Ge- and Sn-implanted samples. These results suggest the presence of defects that interact with Sn or hydrogen atoms. This indicates the possibility of defect control in Ge substrates by Sn or hydrogen incorporation. Such defect control could yield high-performance Ge-based devices.

  14. Low-voltage and short-channel pentacene field-effect transistors with top-contact geometry using parylene-C shadow masks

    E-Print Network [OSTI]

    Dokmeci, Mehmet

    that of hydro- genated amorphous silicon,6 and their low processing tem- perature makes them more attractive be precisely controlled and defect-free dielectric films can be grown with optimized processing conditions of device parameters, such as drain current, gate delay, and power dissipation, and FET performance

  15. Masked-backlighter technique used to simultaneously image x-ray absorption and x-ray emission from an inertial confinement fusion plasma

    SciTech Connect (OSTI)

    Marshall, F. J., E-mail: fredm@lle.rochester.edu; Radha, P. B. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2014-11-15T23:59:59.000Z

    A method to simultaneously image both the absorption and the self-emission of an imploding inertial confinement fusion plasma has been demonstrated on the OMEGA Laser System. The technique involves the use of a high-Z backlighter, half of which is covered with a low-Z material, and a high-speed x-ray framing camera aligned to capture images backlit by this masked backlighter. Two strips of the four-strip framing camera record images backlit by the high-Z portion of the backlighter, while the other two strips record images aligned with the low-Z portion of the backlighter. The emission from the low-Z material is effectively eliminated by a high-Z filter positioned in front of the framing camera, limiting the detected backlighter emission to that of the principal emission line of the high-Z material. As a result, half of the images are of self-emission from the plasma and the other half are of self-emission plus the backlighter. The advantage of this technique is that the self-emission simultaneous with backlighter absorption is independently measured from a nearby direction. The absorption occurs only in the high-Z backlit frames and is either spatially separated from the emission or the self-emission is suppressed by filtering, or by using a backlighter much brighter than the self-emission, or by subtraction. The masked-backlighter technique has been used on the OMEGA Laser System to simultaneously measure the emission profiles and the absorption profiles of polar-driven implosions.

  16. Characterization of V-shaped defects in 4H-SiC homoepitaxial layers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Lihua; Su, Dong; Kisslinger, Kim; Stach, Eric; Chung, Gil; Zhang, Jie; Thomas, Bernd; Sanchez, Edward K; Mueller, Stephan G.; Hansen, Darren; et al

    2015-05-01T23:59:59.000Z

    Synchrotron white beam x-ray topography images show that faint needle-like surface morphological features observed on the Si-face of 4H-SiC homoepitaxial layers using Nomarski optical microscopy are associated with V shaped stacking faults in the epilayer. KOH etching of the V shaped defect reveals small oval pits connected by a shallow line which corresponding to the surface intersections of two partial dislocations and the stacking fault connecting them. Transmission electron microscopy (TEM) specimens from regions containing the V shaped defects were prepared using focused ion beam milling, and stacking sequences of (85), (50) and (63) are observed at the faulted regionmore »with high resolution TEM. In order to study the formation mechanism of V shaped defect, low dislocation density 4H-SiC substrates were chosen for epitaxial growth, and the corresponding regions before and after epitaxy growth are compared in SWBXT images. It is found that no defects in the substrate are directly associated with the formation of the V shaped defect. Simulation results of the contrast from the two partial dislocations associated with V shaped defect in synchrotron monochromatic beam x-ray topography reveals the opposite sign nature of their Burgers vectors. Therefore, a mechanism of 2D nucleation during epitaxy growth is postulated for the formation of the V shaped defect, which requires elimination of non-sequential 1/4[0001] bilayers from the original structure to create the observed faulted stacking sequence.« less

  17. Studies on intrinsic defects related to Zn vacancy in ZnO nanoparticles

    SciTech Connect (OSTI)

    Singh, V.P. [School of Materials Science and Technology, Indian Institute of Technology (BHU), Varanasi, 221005 (India)] [School of Materials Science and Technology, Indian Institute of Technology (BHU), Varanasi, 221005 (India); Das, D. [UGC-DAE Consortium for Scientific Research, Kolkata Centre (India)] [UGC-DAE Consortium for Scientific Research, Kolkata Centre (India); Rath, Chandana, E-mail: chandanarath@yahoo.com [School of Materials Science and Technology, Indian Institute of Technology (BHU), Varanasi, 221005 (India)] [School of Materials Science and Technology, Indian Institute of Technology (BHU), Varanasi, 221005 (India)

    2013-02-15T23:59:59.000Z

    Graphical abstract: Display Omitted Highlights: ? Williamson–Hall analysis of ZnO indicates strain in the lattice and size is of 20 nm. ? PL shows a broad emission peak in visible range due to native defects. ? Raman active modes corresponding to P6{sub 3}mc and a few additional modes are observed. ? FTIR detects few local vibrational modes of hydrogen attached to zinc vacancies. ? V{sub Zn}-H and Zn + O divacancies are confirmed by PAS. -- Abstract: ZnO being a well known optoelectronic semiconductor, investigations related to the defects are very promising. In this report, we have attempted to detect the defects in ZnO nanoparticles synthesized by the conventional coprecipitation route using various spectroscopic techniques. The broad emission peak observed in photoluminescence spectrum and the non zero slope in Williamson–Hall analysis indicate the defects induced strain in the ZnO lattice. A few additional modes observed in Raman spectrum could be due to the breakdown of the translation symmetry of the lattice caused by defects and/or impurities. The presence of impurities can be ruled out as XRD pattern shows pure wurtzite structure. The presence of the vibrational band related to the Zn vacancies (V{sub Zn}), unintentional hydrogen dopants and their complex defects confirm the defects in ZnO lattice. Positron life time components ?{sub 1} and ?{sub 2} additionally support V{sub Zn} attached to hydrogen and to a cluster of Zn and O di-vacancies respectively.

  18. Screening method for selecting semiconductor substrates having defects below a predetermined level in an oxide layer

    DOE Patents [OSTI]

    Warren, W.L.; Vanheusden, K.J.R.; Schwank, J.R.; Fleetwood, D.M.; Shaneyfelt, M.R.; Winokur, P.S.; Devine, R.A.B.

    1998-07-28T23:59:59.000Z

    A method is disclosed for screening or qualifying semiconductor substrates for integrated circuit fabrication. The method comprises the steps of annealing at least one semiconductor substrate at a first temperature in a defect-activating ambient (e.g. hydrogen, forming gas, or ammonia) for sufficient time for activating any defects within on oxide layer of the substrate; measuring a defect-revealing electrical characteristic of at least a portion of the oxide layer for determining a quantity of activated defects therein; and selecting substrates for which the quantity of activated defects is below a predetermined level. The defect-revealing electrical characteristic may be a capacitance-versus voltage (C-V) characteristic or a current-versus-voltage (I-V) characteristic that is dependent on an electrical charge in the oxide layer generated by the activated defects. Embodiments of the present invention may be applied for screening any type of semiconductor substrate or wafer having an oxide layer formed thereon or therein. This includes silicon-on-insulator substrates formed by a separation by the implantation of oxygen (SIMOX) process or the bond and etch back silicon-on-insulator (BESOI) process, as well as silicon substrates having a thermal oxide layer or a deposited oxide layer. 5 figs.

  19. Effect of implanted species on thermal evolution of ion-induced defects in ZnO

    SciTech Connect (OSTI)

    Azarov, A. Yu.; Rauwel, P.; Kuznetsov, A. Yu.; Svensson, B. G. [Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo (Norway); Hallén, A. [Royal Institute of Technology, KTH-ICT, Electrum 229, SE-164 40, Kista, Stockholm (Sweden); Du, X. L. [Institute of Physics, The Chinese Academy of Sciences, Beijing 100190 (China)

    2014-02-21T23:59:59.000Z

    Implanted atoms can affect the evolution of ion-induced defects in radiation hard materials exhibiting a high dynamic annealing and these processes are poorly understood. Here, we study the thermal evolution of structural defects in wurtzite ZnO samples implanted at room temperature with a wide range of ion species (from {sup 11}B to {sup 209}Bi) to ion doses up to 2?×?10{sup 16}?cm{sup ?2}. The structural disorder was characterized by a combination of Rutherford backscattering spectrometry, nuclear reaction analysis, and transmission electron microscopy, while secondary ion mass spectrometry was used to monitor the behavior of both the implanted elements and residual impurities, such as Li. The results show that the damage formation and its thermal evolution strongly depend on the ion species. In particular, for F implanted samples, a strong out-diffusion of the implanted ions results in an efficient crystal recovery already at 600?°C, while co-implantation with B (via BF{sub 2}) ions suppresses both the F out-diffusion and the lattice recovery at such low temperatures. The damage produced by heavy ions (such as Cd, Au, and Bi) exhibits a two-stage annealing behavior where efficient removal of point defects and small defect clusters occurs at temperatures ?500?°C, while the second stage is characterized by a gradual and partial annealing of extended defects. These defects can persist even after treatment at 900?°C. In contrast, the defects produced by light and medium mass ions (O, B, and Zn) exhibit a more gradual annealing with increasing temperature without distinct stages. In addition, effects of the implanted species may lead to a nontrivial defect evolution during the annealing, with N, Ag, and Er as prime examples. In general, the obtained results are interpreted in terms of formation of different dopant-defect complexes and their thermal stability.

  20. Failure Pressure Estimates of Steam Generator Tubes Containing Wear-type Defects

    SciTech Connect (OSTI)

    Yoon-Suk Chang; Jong-Min Kim; Nam-Su Huh; Young-Jin Kim [School of Mechanical Engineering, Sungkyunkwan University (Korea, Republic of); Seong Sik Hwang; Joung-Soo Kim [Korea Atomic Energy Research Institute (Korea, Republic of)

    2006-07-01T23:59:59.000Z

    It is commonly requested that steam generator tubes with defects exceeding 40% of wall thickness in depth should be plugged to sustain all postulated loads with appropriate margin. The critical defect dimensions have been determined based on the concept of plastic instability. This criterion, however, is known to be too conservative for some locations and types of defects. In this context, the accurate failure estimation for steam generator tubes with a defect draws increasing attention. Although several guidelines have been developed and are used for assessing the integrity of defected tubes, most of these guidelines are related to stress corrosion cracking or wall-thinning phenomena. As some of steam generator tubes are also failed due to fretting and so on, alternative failure estimation schemes for relevant defects are required. In this paper, three-dimensional finite element (FE) analyses are carried out under internal pressure condition to simulate the failure behavior of steam generator tubes with different defect configurations; elliptical wastage type, wear scar type and rectangular wastage type defects. Maximum pressures based on material strengths are obtained from more than a hundred FE results to predict the failure of the steam generator tube. After investigating the effect of key parameters such as wastage depth, wastage length and wrap angle, simplified failure estimation equations are proposed in relation to the equivalent stress at the deepest point in wastage region. Comparison of failure pressures predicted according to the proposed estimation scheme with some corresponding burst test data shows good agreement, which provides a confidence in the use of the proposed equations to assess the integrity of steam generator tubes with wear-type defects. (authors)

  1. Parity-odd anomalies and correlation functions on conical defects

    E-Print Network [OSTI]

    Cvitan, Maro; Pallua, Silvio; Smoli?, Ivica; Štemberga, Tamara

    2015-01-01T23:59:59.000Z

    We analyse parity-odd ("P-type") surface anomalies ("Graham-Witten anomalies") of energy-momentum correlators in conformal field theories defined in d-dimensional spacetime supplemented with a conical defect, with an emphases on d=4 and d=3 cases. In d=4 we show that the trace anomaly will receive such surface contribution if the bulk trace anomaly contains P-type anomaly given by Pontryagin (pseudo)tensor, and as a consequence 2-point correlation function of energy-momentum tensor in flat spacetime will be nonvanishing as it receives corresponding surface contributions. In the process, we construct the most general P-type surface trace anomaly on singular 2-dimensional surface in 4-dimensional spacetime by performing consistency analysis. We show that there are two independent terms, one is the outer curvature (pseudo)scalar and the other is quadratic in the traceless part of the second fundamental tensor. For the special case of conical singularity we calculate the coefficient of the first term. Though we w...

  2. Control of Suspect/Counterfeit and Defective Items

    SciTech Connect (OSTI)

    Sheriff, Marnelle L.

    2013-09-03T23:59:59.000Z

    This procedure implements portions of the requirements of MSC-MP-599, Quality Assurance Program Description. It establishes the Mission Support Alliance (MSA) practices for minimizing the introduction of and identifying, documenting, dispositioning, reporting, controlling, and disposing of suspect/counterfeit and defective items (S/CIs). employees whose work scope relates to Safety Systems (i.e., Safety Class [SC] or Safety Significant [SS] items), non-safety systems and other applications (i.e., General Service [GS]) where engineering has determined that their use could result in a potential safety hazard. MSA implements an effective Quality Assurance (QA) Program providing a comprehensive network of controls and verification providing defense-in-depth by preventing the introduction of S/CIs through the design, procurement, construction, operation, maintenance, and modification of processes. This procedure focuses on those safety systems, and other systems, including critical load paths of lifting equipment, where the introduction of S/CIs would have the greatest potential for creating unsafe conditions.

  3. Hydrogen decoration of radiation damage induced defect structures

    SciTech Connect (OSTI)

    Kirnstötter, S. [Institute of Solid State Physics, Graz University of Technology, 8010 Graz and Infineon Technologies Austria AG, 9500 Villach (Austria); Faccinelli, M.; Hadley, P. [Institute of Solid State Physics, Graz University of Technology, 8010 (Austria); Schustereder, W. [Infineon Technologies Austria AG, 9500 Villach (Austria); Laven, J. G.; Schulze, H.-J. [Infineon Technologies AG, 81726 Munich (Germany)

    2014-02-21T23:59:59.000Z

    The defect complexes that are formed when protons with energies in the MeV-range were implanted into high-purity silicon were investigated. After implantation, the samples were annealed at 400 °C or 450 °C for times ranging between 15 minutes and 30 hours. The resistivity of the samples was then analyzed by Spreading Resistance Profiling (SRP). The resistivity shows minima where there is a high carrier concentration and it is possible to extract the carrier concentration from the resistivity data. Initially, there is a large peak in the carrier concentration at the implantation depth where most of the hydrogen is concentrated. For longer anneals, this peak widens as the hydrogen diffuses away from the implantation depth. Following the changes in resistivity as a function of annealing time allows us to characterize the diffusion of hydrogen through these samples. Differences in the diffusion were observed depending on whether the silicon was grown by the magnetic Czochralski (m:Cz) method or the Float zone (Fz) method.

  4. The Defect Induced Mix Experiment (DIME) for NIF

    SciTech Connect (OSTI)

    Schmitt, Mark J [Los Alamos National Laboratory; Bradley, Paul A [Los Alamos National Laboratory; Cobble, James A [Los Alamos National Laboratory; Hakel, Peter [Los Alamos National Laboratory; Hsu, Scott C [Los Alamos National Laboratory; Krasheninnikova, Natalia S [Los Alamos National Laboratory; Kyrala, George A [Los Alamos National Laboratory; Murphy, Thomas J [Los Alamos National Laboratory; Obrey, Kimberly A [Los Alamos National Laboratory; Shah, Rahul C [Los Alamos National Laboratory; Tregillis, Ian L [Los Alamos National Laboratory

    2012-06-18T23:59:59.000Z

    LANL will perform two Defect Induced Mix Experiment (DIME) implosion campaigns on NIF in July and September, 2012. This presentation describes the goals for these shots and the experimental configuration and diagnostic set up to collect the appropriate data. The first two-shot campaign will focus on executing polar direct drive (PDD) implosions of plastic CH capsules filled with deuterium gas. Gas filling will be performed through a fill tube at target chamber center. A vanadium backligher foil will provide x-rays to radiograph the last half of the implosion to compare the implosion trajectory with modeling predictions. An equatorial groove in one of the capsules will be present to determine its effect on implosion dynamics. The second DIME campaign will commission and use a spectral imager (MMI) to examine the evolution of thin capsule layers doped with either Ge or Ga at 1.85%. Spectral line emission from these layers will quantify the mix width at the inner shell radius and near an equatorial groove feature.

  5. Current rectification, switching, polarons, and defects in molecular electronic devices

    E-Print Network [OSTI]

    A. M. Bratkovsky

    2006-11-06T23:59:59.000Z

    Devices for nano- and molecular size electronics are currently a focus of research aimed at an efficient current rectification and switching. A few generic molecular scale devices are reviewed here on the basis of first-principles and model approaches. Current rectification by (ballistic) molecular quantum dots can produce the rectification ratio ~100. Current switching due to conformational changes in the molecules is slow, on the order of a few kHz. Fast switching (~1THz) may be achieved, at least in principle, in a degenerate molecular quantum dot with strong coupling of electrons with vibrational excitations. We show that the mean-field approach fails to properly describe intrinsic molecular switching and present an exact solution to the problem. Defects in molecular films result in spurious peaks in conductance, apparent negative differential resistance, and may also lead to unusual temperature and bias dependence of current. The observed switching in many cases is_extrinsic_, caused by changes in molecule-electrode geometry, molecule reconfiguration, metallic filament formation through, and/or changing amount of disorder in a molecular film. We give experimental examples of telegraph "switching" and "hot spot" formation in the molecular films.

  6. Defect formation beyond Kibble-Zurek mechanism and holography

    E-Print Network [OSTI]

    Paul M. Chesler; Antonio M. Garcia-Garcia; Hong Liu

    2015-06-23T23:59:59.000Z

    We study the dynamic after a smooth quench across a continuous transition from the disordered phase to the ordered phase. Based on scaling ideas, linear response and the spectrum of unstable modes, we develop a theoretical framework, valid for any second order phase transition, for the early-time evolution of the condensate in the broken phase. Our analysis unveils a novel period of non-adiabatic evolution after the system passes through the phase transition, where a parametrically large amount of coarsening occurs before a well-defined condensate forms. Our formalism predicts a rate of defect formation parametrically smaller than the Kibble-Zurek prediction and yields a criterion for the break-down of Kibble-Zurek scaling for sufficiently fast quenches. We numerically test our formalism for a thermal quench in a 2 + 1 dimensional holographic superfluid. These findings, of direct relevance in a broad range of fields including cold atom, condensed matter, statistical mechanism and cosmology, are an important step towards a more quantitative understanding of dynamical phase transitions.

  7. Kinetic model for electric-field induced point defect redistribution near semiconductor surfaces

    SciTech Connect (OSTI)

    Gorai, Prashun; Seebauer, Edmund G., E-mail: eseebaue@illinois.edu [Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana, Illinois 61801 (United States)

    2014-07-14T23:59:59.000Z

    The spatial distribution of point defects near semiconductor surfaces affects the efficiency of devices. Near-surface band bending generates electric fields that influence the spatial redistribution of charged mobile defects that exchange infrequently with the lattice, as recently demonstrated for pile-up of isotopic oxygen near rutile TiO{sub 2} (110). The present work derives a mathematical model to describe such redistribution and establishes its temporal dependence on defect injection rate and band bending. The model shows that band bending of only a few meV induces significant redistribution, and that the direction of the electric field governs formation of either a valley or a pile-up.

  8. The RF performance of cavity made from defective niobium material determined by Eddy Current Scanning

    SciTech Connect (OSTI)

    Wu, G.; Cooley, L.; Sergatskov, D.; Ozelis, J.; /Fermilab; Brinkmann, A.; Singer, W.; Singer, X.; /DESY; Pekeler, M.

    2010-10-01T23:59:59.000Z

    Eddy current scanning (ECS) has been used to screen niobium sheets to avoid defective material being used in costly cavity fabrication. The evaluation criterion of this quality control tool is not well understood. Past surface studies showed some features were shallow enough to be removed by chemical etching. The remaining features were identified to be small number of deeper inclusions, but mostly unidentifiable features (by chemical analysis). A real cavity made of defective niobium material has been tested. The cavity achieved high performance with comparable results to the cavities made from defect free cavities. Temperature mapping could help to define the control standard clearly.

  9. Fusion-bonded epoxy coating defects on weld center line of submerged-arc welded pipe

    SciTech Connect (OSTI)

    Sokol, D.R.; Herndon, C.M. (Tenneco Oil Co., Houston, TX (USA))

    1990-08-01T23:59:59.000Z

    The problem of weld center line coating defects in fusion-bonded epoxy coatings has occurred on pipe produced in Europe, North America, and Asia. At various times, the defects have been attributed to coating application practices, powder manufacturing, pipe manufacturing, welding methods, and overly critical inspectors. This article details plant experience and experimental trails that led to the identification of the cause and proof of the solution. The ultimate effect of initial coating defects on cathodic protection requirements is a matter of concern also.

  10. Scattering of linear and nonlinear waves in a waveguide array with a PT-symmetric defect

    SciTech Connect (OSTI)

    Dmitriev, Sergey V.; Suchkov, Sergey V. [Institute for Metals Superplasticity Problems, Russian Academy of Science, Ufa RU-450001 (Russian Federation); Sukhorukov, Andrey A.; Kivshar, Yuri S. [Nonlinear Physics Centre, Research School of Physics and Engineering,Australian National University, Canberra, ACT 0200 (Australia)

    2011-07-15T23:59:59.000Z

    We study the scattering of linear and nonlinear waves in a long waveguide array with a parity-time (PT)-symmetric defect created by two waveguides with balanced gain and loss. We present exact solutions for the scattering of linear waves on such a defect, and then demonstrate numerically that the linear theory can describe, with a good accuracy, the soliton scattering in the case of weak nonlinearity. We reveal that the reflected and transmitted linear and nonlinear waves can be amplified substantially after interaction with the PT-symmetric defect thus allowing an active control of the wave scattering in the array.

  11. Quantum Defects and the Long-Term Behavior of Radial Rydberg Wave Packets

    E-Print Network [OSTI]

    Robert Bluhm; Alan Kostelecky

    1994-10-19T23:59:59.000Z

    We show that a theoretical description of radial Rydberg wave packets in alkali-metal atoms based solely on hydrogenic wave functions and energies is insufficient to explain data that could be obtained in pump-probe experiments with current technology. The modifications to long-term revival times induced by quantum defects cannot be obtained by direct scaling of the hydrogenic results. Moreover, the effects of laser detuning and quantum defects are different. An alternative approach providing analytical predictions using supersymmetry-based quantum-defect theory is presented.

  12. Spin counting in electrically detected magnetic resonance via low-field defect state mixing

    SciTech Connect (OSTI)

    Cochrane, Corey J.; Lenahan, Patrick M. [The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-03-03T23:59:59.000Z

    The work herein describes a method that allows one to measure paramagnetic defect densities in semiconductor and insulator based devices with electrically detected magnetic resonance (EDMR). The method is based upon the mixing of defect states which results from the dipolar coupling of paramagnetic sites at low magnetic fields. We demonstrate the measurement method with spin dependent tunneling in thin film dielectrics; however, the method should be equally applicable to paramagnetic defect density measurements in semiconductors via the more commonly utilized EDMR technique called spin dependent recombination.

  13. Structural defects in GaN revealed by Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Liliental-Weber, Zuzanna

    2014-04-18T23:59:59.000Z

    This paper reviews the various types of structural defects observed by Transmission Electron Microscopy in GaN heteroepitaxial layers grown on foreign substrates and homoepitaxial layers grown on bulk GaN substrates. The structural perfection of these layers is compared to the platelet self-standing crystals grown by High Nitrogen Pressure Solution. Defects in undoped and Mg doped GaN are discussed. Some models explaining the formation of inversion domains in heavily Mg doped layers that are possible defects responsible for the difficulties of p-doping in GaN are also reviewed.

  14. Effect of defects on long-pulse laser-induced damage of two kinds of optical thin films

    SciTech Connect (OSTI)

    Wang Bin; Qin Yuan; Ni Xiaowu; Shen Zhonghua; Lu Jian

    2010-10-10T23:59:59.000Z

    In order to study the effect of defects on the laser-induced damage of different optical thin films, we carried out damage experiments on two kinds of thin films with a 1ms long-pulse laser. Surface-defect and subsurface-defect damage models were used to explain the damage morphology. The two-dimensional finite element method was applied to calculate the temperature and thermal-stress fields of these two films. The results show that damages of the two films are due to surface and subsurface defects, respectively. Furthermore, the different dominant defects for thin films of different structures are discussed.

  15. Solvent Immersion Imprint Lithography. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of polymer disolution was explored for polymer microsystem prototyping, including microfluidics and optofluidics. Polymer films are immersed in a solvent, imprinted and finally...

  16. Exp

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Kwok Patterning of Columnar Defects with Heavy-Ion Lithography in High Temperature Superconductors 2 793 Woods Recoil Decay Tagging Study of the Highly Deformed Proton Emitter...

  17. Assessment of structures and stabilities of defect clusters and surface energies predicted by nine interatomic potentials for UO2

    SciTech Connect (OSTI)

    Stephen A. Taller; Xian-Ming Bai

    2013-11-01T23:59:59.000Z

    The irradiation in nuclear reactors creates many point defects and defect clusters in uranium dioxide (UO2) and their evolution severely degrades the thermal and mechanical properties of the nuclear fuels. Previously many empirical interatomic potentials have been developed for modeling defect production and evolution in UO2. However, the properties of defect clusters and extended defects are usually not fitted into these potentials. In this work nine interatomic potentials for UO2 are examined by using molecular statics and molecular dynamics to assess their applicability in predicting the properties of various types of defect clusters in UO2. The binding energies and structures for these defect clusters have been evaluated for each potential. In addition, the surface energies of voids of different radii and (1 1 0) flat surfaces predicted by these potentials are also evaluated. It is found that both good agreement and significant discrepancies exist for these potentials in predicting these properties. For oxygen interstitial clusters, these potentials predict significantly different defect cluster structures and stabilities; For defect clusters consisting of both uranium and oxygen defects, the prediction is in better agreement; The surface energies predicted by these potentials have significant discrepancies, and some of them are much higher than the experimentally measured values. The results from this work can provide insight on interpreting the outcome of atomistic modeling of defect production using these potentials and may provide guidelines for choosing appropriate potential models to study problems of interest in UO2.

  18. Impact of dislocations and dangling bond defects on the electrical performance of crystalline silicon thin films

    SciTech Connect (OSTI)

    Steffens, S.; Becker, C., E-mail: christiane.becker@helmholtz-berlin.de; Amkreutz, D.; Schnegg, A.; Abou-Ras, D.; Lips, K.; Rech, B. [Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin (Germany); Klossek, A. [Brandenburgische Technische Universität, Cottbus (Germany); Kittler, M. [Brandenburgische Technische Universität, Cottbus (Germany); IHP Microelectronics, Frankfurt (Oder) (Germany); Chen, Y.-Y. [Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin (Germany); Green Energy and Environment Research Labs, Industrial Technology Research Institute, Hsinchu, Taiwan (China); Klingsporn, M. [IHP Microelectronics, Frankfurt (Oder) (Germany)

    2014-07-14T23:59:59.000Z

    A wide variety of liquid and solid phase crystallized silicon films are investigated in order to determine the performance limiting defect types in crystalline silicon thin-film solar cells. Complementary characterization methods, such as electron spin resonance, photoluminescence, and electron microscopy, yield the densities of dangling bond defects and dislocations which are correlated with the electronic material quality in terms of solar cell open circuit voltage. The results indicate that the strongly differing performance of small-grained solid and large-grain liquid phase crystallized silicon can be explained by intra-grain defects like dislocations rather than grain boundary dangling bonds. A numerical model is developed containing both defect types, dislocations and dangling bonds, describing the experimental results.

  19. Software defect tracking during new product development of a computer system

    E-Print Network [OSTI]

    Curhan, Lisa A., 1961-

    2005-01-01T23:59:59.000Z

    Software defects (colloquially known as "bugs") have a major impact on the market acceptance and profitability of computer systems. Sun Microsystems markets both hardware and software for a wide variety of customer needs. ...

  20. National market cow and bull beef quality audit-2007: a survey of producer-related defects

    E-Print Network [OSTI]

    Nicholson, John David Whitson

    2009-05-15T23:59:59.000Z

    Packing plants (n = 23), were audited for producer-related defects found in cull cows and bulls. Interviews, live animal and carcass evaluations, and subprimal evaluations were conducted during each audit. A drastic reduction in downer incidence...

  1. Damage initiation, progression and failure of polymer matrix composites due to manufacturing induced defects 

    E-Print Network [OSTI]

    Chowdhury, Khairul Alam

    2007-09-17T23:59:59.000Z

    In polymer matrix composites (PMCs) manufacturing processes can induce de- fects, e.g., voids, fiber misalignment, irregular fiber distribution in the cross-section and broken fibers. The effects of such defects can be beneficial or deleterious de...

  2. Integrated Droplet Routing and Defect Tolerance in the Synthesis of Digital

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    11 Integrated Droplet Routing and Defect Tolerance in the Synthesis of Digital Microfluidic Biochips TAO XU and KRISHNENDU CHAKRABARTY Duke University Microfluidic biochips are revolutionizing high to digital microfluidic platforms, the need for design automation techniques is being increasingly felt

  3. Neurophysiological Defects and Neuronal Gene Deregulation in Drosophila mir-124 Mutants

    E-Print Network [OSTI]

    Oregon, University of

    Neurophysiological Defects and Neuronal Gene Deregulation in Drosophila mir-124 Mutants Kailiang and Neuronal Gene Deregulation in Drosophila mir-124 Mutants. PLoS Genet 8(2): e1002515. doi:10.1371/journal

  4. DISSERTATION Role of the Cu-O Defect in CdTe Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION Role of the Cu-O Defect in CdTe Solar Cells Submitted by Caroline R. Corwine Colorado State University Fort Collins, Colorado Summer 2006 #12;#12;ABSTRACT OF DISSERTATION ROLE

  5. Hydrogen effects on the point defect spectrum in Fe-C alloys

    E-Print Network [OSTI]

    Monasterio Velásquez, Paul Rene

    2008-01-01T23:59:59.000Z

    As part of a multi-scale approach for modeling hydrogen embrittlement in hardened steels we have investigated, employing density functional theory methods, the stability and concentrations of the point defect clusters ...

  6. Electrical properties and defect structures of praseodymium-cerium oxide solid solutions

    E-Print Network [OSTI]

    Stefanik, Todd Stanley, 1973-

    2004-01-01T23:59:59.000Z

    A defect chemistry model consistent with observed trends in the pO2 and temperature dependence of electrical conductivity in praseodymium cerium oxide (PCO) was developed. Four point DC conductivity measurements were made ...

  7. Entropy and Kinetics of Point-Defects in Two-Dimensional Dipolar Crystals

    E-Print Network [OSTI]

    Wolfgang Lechner; David Polster; Georg Maret; Christoph Dellago; Peter Keim

    2015-02-18T23:59:59.000Z

    We study in experiment and with computer simulation the free energy and the kinetics of vacancy and interstitial defects in two-dimensional dipolar crystals. The defects appear in different local topologies which we characterize by their point group symmetry; $C_n$ is the n-fold cyclic group and $D_n$ is the dihedral group, including reflections. The frequency of different local topologies is not determined by their almost degenerate energies but dominated by entropy for symmetric configurations. The kinetics of the defects is fully reproduced by a master equation in a multi-state Markov model. In this model, the system is described by the state of the defect and the time evolution is given by transitions occurring with particular rates. These transition rate constants are extracted from experiments and simulations using an optimisation procedure. The good agreement between experiment, simulation and master equation thus provides evidence for the accuracy of the model.

  8. An analytical study of rail grinding optimization for rail-head fatigue defect prevention

    E-Print Network [OSTI]

    Jones, Scott Laurence

    1997-01-01T23:59:59.000Z

    and increased train traffic on the remaining routes. These changes in railroad industry practice have caused an increase in the rate of occurrence of rail head fatigue defects, one potential cause of train derailment. The primary form of maintenance employed...

  9. PHYSICAL REVIEW B 86, 165440 (2012) Graphene flakes with defective edge terminations: Universal and topological aspects,

    E-Print Network [OSTI]

    Yannouleas, Constantine

    2012-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 86, 165440 (2012) Graphene flakes with defective edge terminations: Universal (as a function of the magnetic field) are presented for trigonal graphene nanoflakes. The electronic spectra of trigonal graphene nanoflakes with reczag edge terminations exhibit certain unique

  10. Stochastic Damage Evolution under Static and Fatigue Loading in Composites with Manufacturing Defects

    E-Print Network [OSTI]

    Huang, Yongxin

    2012-07-16T23:59:59.000Z

    In this dissertation, experimental investigations and theoretical studies on the stochastic matrix cracking evolution under static and fatigue loading in composite laminates with defects are presented. The presented work demonstrates a methodology...

  11. Defect-Enhanced Charge Transfer by Ion-Solid Interactions in...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    transfer effects on recoil atoms. Citation: Gao F, HY Xiao, XT Zu, M Posselt, and WJ Weber.2009."Defect-Enhanced Charge Transfer by Ion-Solid Interactions in SiC using...

  12. Higher-Order Mass Defect Analysis for Mass Spectra of Complex...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    high-resolution mass spectrum of crude oil containing nearly 13,000 peaks. Citation: Roach PJ, J Laskin, and A Laskin.2011."Higher-Order Mass Defect Analysis for Mass Spectra of...

  13. Ultrasonic nondestructive evaluation and imaging of defects in reinforced cementitious materials

    E-Print Network [OSTI]

    Wang, Ji-yong, 1967-

    2003-01-01T23:59:59.000Z

    Characterization of defect is one of the important objectives of nondestructive evaluation (NDE) for condition assessment of structures. Among many other NDE techniques, ultrasonic methods play a prominent role in the both ...

  14. Defects in paramagnetic Co-doped ZnO films studied by transmission...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Abstract: We have studied planar defects in epitaxial Co:ZnO dilute magnetic semiconductor thin films deposited on c-plane sapphire (Al2O3) and the Co:ZnOAl2O3...

  15. Defect-Band Emission Photoluminescence Imaging on Multi-Crystalline Si Solar Cells: Preprint

    SciTech Connect (OSTI)

    Yan, F.; Johnston, S.; Zaunbrecher, K.; Al-Jassim, M.; Sidelkheir, O.; Blosse, A.

    2011-07-01T23:59:59.000Z

    Defect-band photoluminescence (PL) imaging with an InGaAs camera was applied to multicrystalline silicon (mc-Si) wafers, which were taken from different heights of different Si bricks. Neighboring wafers were picked at six different processing steps, from as-cut to post-metallization. By using different cut-off filters, we were able to separate the band-to-band emission images from the defect-band emission images. On the defect-band emission images, the bright regions that originate from the grain boundaries and defect clusters were extracted from the PL images. The area fraction percentage of these regions at various processing stages shows a correlation with the final cell electrical parameters.

  16. Graphene flakes with defective edge terminations: Universal and topological aspects, and one-dimensional quantum behavior

    E-Print Network [OSTI]

    Yannouleas, Constantine

    Graphene flakes with defective edge terminations: Universal and topological aspects, and one graphene nanoflakes with reconstructed zigzag edges, where a succes- sion of pentagons and heptagons these spectra. The electronic spectra of trigonal graphene nanoflakes with reczag edge terminations exhibit

  17. Optimal suppression of defect generation during a passage across a quantum critical point

    E-Print Network [OSTI]

    Ning Wu; Arun Nanduri; Herschel Rabitz

    2014-12-09T23:59:59.000Z

    The dynamics of quantum phase transitions are inevitably accompanied by the formation of defects when crossing a quantum critical point. For a generic class of quantum critical systems, we solve the problem of minimizing the production of defects through the use of a gradient-based deterministic optimal control algorithm. By considering a finite size quantum Ising model with a tunable global transverse field, we show that an optimal power law quench of the transverse field across the Ising critical point works well at minimizing the number of defects, in spite of being drawn from a subset of quench profiles. These power law quenches are shown to be inherently robust against noise. The optimized defect density exhibits a transition at a critical ratio of the quench duration to the system size, which we argue coincides with the intrinsic speed limit for quantum evolution.

  18. Impact of defect type on hydrogen passivation effectiveness in multicrystalline silicon solar cells

    E-Print Network [OSTI]

    Bertoni, Mariana I.

    In this work we examine the effectiveness of hydrogen passivation at grain boundaries as a function of defect type and microstructure in multicrystalline silicon. We analyze a specially prepared solar cell with alternating ...

  19. Effects of topological defects and local curvature on the electronic properties of planar graphene

    E-Print Network [OSTI]

    Alberto Cortijo; María A. H. Vozmediano

    2006-12-14T23:59:59.000Z

    A formalism is proposed to study the electronic and transport properties of graphene sheets with corrugations as the one recently synthesized. The formalism is based on coupling the Dirac equation that models the low energy electronic excitations of clean flat graphene samples to a curved space. A cosmic string analogy allows to treat an arbitrary number of topological defects located at arbitrary positions on the graphene plane. The usual defects that will always be present in any graphene sample as pentagon-heptagon pairs and Stone-Wales defects are studied as an example. The local density of states around the defects acquires characteristic modulations that could be observed in scanning tunnel and transmission electron microscopy.

  20. Origin of radiation tolerance in 3C-SiC with nanolayered planar defects

    SciTech Connect (OSTI)

    Ishimaru, Dr. Manabu [Osaka University; Zhang, Yanwen [ORNL; Shannon, Prof. Steven [North Carolina State University; Weber, William J [ORNL

    2013-01-01T23:59:59.000Z

    We have recently found that the radiation tolerance of SiC is highly enhanced by introducing nanolayers of stacking faults and twins [Y. Zhang et al., Phys. Chem. Chem. Phys. 14, 13429 (2012)]. To reveal the origin of this radiation resistance, we used in situ transmission electron microscopy to examine structural changes induced by electron beam irradiation in 3C-SiC containing nanolayers of (111) planar defects. We found that preferential amorphization, when it does occur, takes place at grain boundaries and at 111 and 111 planar defects. Radiationinduced point defects, such as interstitials and vacancies, migrate two-dimensionally between the (111) planar defects, which probably enhances the damage recovery.