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Title: Optical properties of sputtered amorphous beryllium nitride thin films

Abstract

The optical properties of amorphous beryllium nitride (a-Be{sub 3}N{sub 2}) thin films deposited on Si (100) at temperature <50 degree sign C using reactive rf sputtering deposition were examined in the wavelength range of 280-1600 nm. X-ray diffraction of the films showed no structure, suggesting the Be{sub 3}N{sub 2} films grown on the Si (100) substrates are amorphous. The thicknesses and optical constants of the films were derived from variable-angle spectroscopic ellipsometry measurements using the Cauchy-Urbach model. Refractive indices and extinction coefficients of the films were determined to be in the range n=1.98-2.28 and {kappa}=0.0002-0.08, respectively. Analysis of the absorption coefficient shows the optical absorption edge of a-Be{sub 3}N{sub 2} films to be 4.12{+-}0.01 eV. These values were in excellent agreement with the photoluminescence measurements (4.18 eV). The surface morphology was characterized by atomic force microscopy. The surfaces of the films were very smooth and their average roughnesses were measured to be in the range of 0.36-2.4 nm. An effective medium approximation model of 50% Be{sub 3}N{sub 2} and 50% voids was used in the ellipsometric fitting procedure. The spectral dependence of transmissivity of the films was investigated at different angles of incidence (20 degree sign -80 degree sign ).more » The a-Be{sub 3}N{sub 2} films shown high transmissivity (80%-99%) in the visible and near infrared regions.« less

Authors:
; ;  [1];  [2]
  1. Department of Physics, Al-Hussein Bin Talal University, Ma'an (Jordan)
  2. (United States)
Publication Date:
OSTI Identifier:
20982892
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 10; Other Information: DOI: 10.1063/1.2738393; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; AMORPHOUS STATE; APPROXIMATIONS; ATOMIC FORCE MICROSCOPY; BERYLLIUM NITRIDES; ELLIPSOMETRY; EV RANGE 01-10; INCIDENCE ANGLE; MORPHOLOGY; PHOTOLUMINESCENCE; REFRACTIVE INDEX; ROUGHNESS; SPUTTERING; SUBSTRATES; SURFACE COATING; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; THICKNESS; THIN FILMS; X-RAY DIFFRACTION

Citation Formats

Khoshman, J. M., Khan, A., Kordesch, M. E., and Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701. Optical properties of sputtered amorphous beryllium nitride thin films. United States: N. p., 2007. Web. doi:10.1063/1.2738393.
Khoshman, J. M., Khan, A., Kordesch, M. E., & Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701. Optical properties of sputtered amorphous beryllium nitride thin films. United States. doi:10.1063/1.2738393.
Khoshman, J. M., Khan, A., Kordesch, M. E., and Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701. Tue . "Optical properties of sputtered amorphous beryllium nitride thin films". United States. doi:10.1063/1.2738393.
@article{osti_20982892,
title = {Optical properties of sputtered amorphous beryllium nitride thin films},
author = {Khoshman, J. M. and Khan, A. and Kordesch, M. E. and Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701},
abstractNote = {The optical properties of amorphous beryllium nitride (a-Be{sub 3}N{sub 2}) thin films deposited on Si (100) at temperature <50 degree sign C using reactive rf sputtering deposition were examined in the wavelength range of 280-1600 nm. X-ray diffraction of the films showed no structure, suggesting the Be{sub 3}N{sub 2} films grown on the Si (100) substrates are amorphous. The thicknesses and optical constants of the films were derived from variable-angle spectroscopic ellipsometry measurements using the Cauchy-Urbach model. Refractive indices and extinction coefficients of the films were determined to be in the range n=1.98-2.28 and {kappa}=0.0002-0.08, respectively. Analysis of the absorption coefficient shows the optical absorption edge of a-Be{sub 3}N{sub 2} films to be 4.12{+-}0.01 eV. These values were in excellent agreement with the photoluminescence measurements (4.18 eV). The surface morphology was characterized by atomic force microscopy. The surfaces of the films were very smooth and their average roughnesses were measured to be in the range of 0.36-2.4 nm. An effective medium approximation model of 50% Be{sub 3}N{sub 2} and 50% voids was used in the ellipsometric fitting procedure. The spectral dependence of transmissivity of the films was investigated at different angles of incidence (20 degree sign -80 degree sign ). The a-Be{sub 3}N{sub 2} films shown high transmissivity (80%-99%) in the visible and near infrared regions.},
doi = {10.1063/1.2738393},
journal = {Journal of Applied Physics},
number = 10,
volume = 101,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • Abstract not provided.
  • Amorphous vanadium oxide (VO{sub x}) is a component found in composite nanocrystalline VO{sub x} thin films. These types of composite films are used as thermistors in pulsed biased uncooled infrared imaging devices when containing face centered cubic vanadium monoxide phase crystallites, and substantial fractions of amorphous material in the composite are necessary to optimize device electrical properties. Similarly, optoelectronic devices exploiting the metal-to-semiconductor transition contain the room-temperature monoclinic or high-temperature (>68 deg. C) rutile vanadium dioxide phase. Thin films of VO{sub x} exhibiting the metal-to-semiconductor transition are typically polycrystalline or nanocrystalline, implying that significant amounts of disordered, amorphous material ismore » present at grain boundaries or surrounding the crystallites and can impact the overall optical or electronic properties of the film. The performance of thin film material for either application depends on both the nature of the crystalline and amorphous components, and in this work we seek to isolate and study amorphous VO{sub x}. VO{sub x} thin films were deposited by pulsed dc reactive magnetron sputtering to produce amorphous materials with oxygen contents {>=}2, which were characterized electrically by temperature dependent current-voltage measurements and optically characterized by spectroscopic ellipsometry. Film resistivity, thermal activation energy, and complex dielectric function spectra from 0.75 to 6.0 eV were used to identify the impact of microstructural variations including composition and density.« less
  • Critical current and flux pinning were examined for ion-beam sputtered (IBS)= amorphous beryllium (a-Be) thin films with T/sub c/ 6 K. Pinning forces in IBS a-Be films were one or more than one order of magnitude smaller than those for crystalline superconductors, but were still rather large for amorphous superconductors. The viscosity coefficient for IBS a-Be was very small, 1--2 x 10/sup -9/ N s/m/sup 2/, which was only a few tenths as large as viscosity coefficients for other metallic superconductors. Write operation characteristics for Abrikosov vortex memory with an IBS a-Be vortex storage region was tested. The write currentmore » level was reduced to about two thirds of that for fine-grained PbInAu previously reported. IBS a-Be films were proved to be a potential material for use in an Abrikosov vortex memory.« less
  • We have investigated the growth of the c-axis oriented aluminum nitride (AlN) thin films on (100) silicon by reactive dc magnetron sputtering at low temperature, considering the effect of the magnet configuration on plasma and film properties. It appears that a magnet modification can significantly modify both the plasma characteristics and the film properties. Electrical and optical characterizations of the plasma phase highlight that depending on the magnet configuration, two very different types of deposition process can be involved in the same deposition chamber. On the one hand, with a balanced magnetron (type 1), the deposition process enhances the productionmore » of AlN dimers in the plasma phase and enables to synthesize AlN films with different preferential orientations (100, 002, and even 101). On the other hand, a strongly unbalanced magnetron (type 2) provides a limited production of AlN species in the plasma phase and a strong increase in the ratio of ions to metal atom flux on the growing films. In the latter case, the ion energy provided by the ion flux to the growing film is typically in the 20-30 eV range. Thus, dense (002) oriented films with high crystalline quality are obtained without any substrate heating.« less