Method for protecting chip corners in wet chemical etching of wafers

Hui, Wing C

Title: Method for protecting chip corners in wet chemical etching of wafers

Abstract

The present invention is a corner protection mask design that protects chip corners from undercutting during anisotropic etching of wafers. The corner protection masks abut the chip corner point and extend laterally from segments along one or both corner sides of the corner point, forming lateral extensions. The protection mask then extends from the lateral extensions, parallel to the direction of the corner side of the chip and parallel to scribe lines, thus conserving wafer space. Unmasked bomb regions strategically formed in the protection mask facilitate the break-up of the protection mask during etching. Corner protection masks are useful for chip patterns with deep grooves and either large or small chip mask areas. Auxiliary protection masks form nested concentric frames that etch from the center outward are useful for small chip mask patterns. The protection masks also form self-aligning chip mask areas. The present invention is advantageous for etching wafers with thin film windows, microfine and micromechanical structures, and for forming chip structures more elaborate than presently possible.

Inventors:

Hui, Wing C ^[1]

Campbell, CA

Issue Date:: 1994-01-01

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

OSTI Identifier:: 869158

Patent Number(s):: 5286343

Assignee:: Regents of University of California (Oakland, CA)

Patent Classifications (CPCs):: H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES

Show more

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES
H01L21/3083 - {characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane}

Show less

DOE Contract Number:: W-7405-ENG-48

Resource Type:: Patent

Country of Publication:: United States

Language:: English

Subject:: method; protecting; chip; corners; wet; chemical; etching; wafers; corner; protection; mask; design; protects; undercutting; anisotropic; masks; abut; extend; laterally; segments; forming; lateral; extensions; extends; parallel; direction; scribe; lines; conserving; wafer; space; unmasked; bomb; regions; strategically; formed; facilitate; break-up; useful; patterns; deep; grooves; auxiliary; form; nested; concentric; frames; etch; center; outward; self-aligning; advantageous; film; windows; microfine; micromechanical; structures; elaborate; presently; micromechanical structure; chemical etching; micromechanical structures; wet chemical; protection mask; anisotropic etching; mask pattern; chip corners; film window; corner protection; mechanical structure; chip corner; /216/156/

Citation Formats


                    Hui, Wing C. Method for protecting chip corners in wet chemical etching of wafers.  United States: N. p., 1994. 
        Web.

Copy to clipboard


                    Hui, Wing C. Method for protecting chip corners in wet chemical etching of wafers.  United States.

Copy to clipboard


                    Hui, Wing C. Sat .  
        "Method for protecting chip corners in wet chemical etching of wafers".  United States.  https://www.osti.gov/servlets/purl/869158.

Copy to clipboard


                    
@article{osti_869158,

  title        = {Method for protecting chip corners in wet chemical etching of wafers},

  author       = {Hui, Wing C},

  abstractNote = {The present invention is a corner protection mask design that protects chip corners from undercutting during anisotropic etching of wafers. The corner protection masks abut the chip corner point and extend laterally from segments along one or both corner sides of the corner point, forming lateral extensions. The protection mask then extends from the lateral extensions, parallel to the direction of the corner side of the chip and parallel to scribe lines, thus conserving wafer space. Unmasked bomb regions strategically formed in the protection mask facilitate the break-up of the protection mask during etching. Corner protection masks are useful for chip patterns with deep grooves and either large or small chip mask areas. Auxiliary protection masks form nested concentric frames that etch from the center outward are useful for small chip mask patterns. The protection masks also form self-aligning chip mask areas. The present invention is advantageous for etching wafers with thin film windows, microfine and micromechanical structures, and for forming chip structures more elaborate than presently possible.},

  doi          = {},

  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {1994},

  month        = {1}

}

Copy to clipboard

Patent:

Save / Share:

Export Metadata

Save to My Library

Works referenced in this record:

Silicon as a mechanical material
journal, May 1982

Petersen, K. E.
Proceedings of the IEEE, Vol. 70, Issue 5
https://doi.org/10.1109/PROC.1982.12331

Fabrication of Non‐Underetched Convex Corners in Anisotropic Etching of (100)‐Silicon in Aqueous KOH with Respect to Novel Micromechanic Elements
journal, December 1990

Mayer, G. K.; Offereins, H. L.; Sandmaier, H.
Journal of The Electrochemical Society, Vol. 137, Issue 12
https://doi.org/10.1149/1.2086334

Mesa structure formation using potassium hydroxide and ethylene diamine based etchants
conference, January 1988

Chang, S. -C.; Hicks, D. B.
IEEE Technical Digest on Solid-State Sensor and Actuator Workshop
https://doi.org/10.1109/SOLSEN.1988.26446

Corner compensation techniques in anisotropic etching of
conference, January 1991

Sandmaier, H.; Offereins, H. L.; Kuhl, K.
TRANSDUCERS '91: 1991 International Conference on Solid-State Sensors and Actuators. Digest of Technical Papers
https://doi.org/10.1109/SENSOR.1991.148910

Compensating corner undercutting in anisotropic etching of (100) silicon
journal, June 1989

Wu, Xian-Ping; Ko, Wen H.
Sensors and Actuators, Vol. 18, Issue 2
https://doi.org/10.1016/0250-6874(89)87019-2

Similar Records in DOE Patents and OSTI.GOV collections:

Method for protecting chip corners in wet chemical etching of wafers

Patent Hui, W C

The present invention is a corner protection mask design that protects chip corners from undercutting during anisotropic etching of wafers. The corner protection masks abut the chip corner point and extend laterally from segments along one or both corner sides of the corner point, forming lateral extensions. The protection mask then extends from the lateral extensions, parallel to the direction of the corner side of the chip and parallel to scribe lines, thus conserving wafer space. Unmasked bomb regions strategically formed in the protection mask facilitate the break-up of the protection mask during etching. Corner protection masks are useful formore » « less
Technique for protecting chip corners in wet chemical etching of silicon wafers

Technical Report Hui, Wing C

When a silicon wafer is under wet chemical etching, any outer comers of a chip may face severe undercutting. This undercutting problem is extremely serious for the boundary comers of the chips; and very often it can limit the compactness in the design of the chips. A special etching mask pattern was developed for protecting the boundary comers of the chips under wet chemical etching. The main central part of this pattern could prevent any undercutting at the comers during the etching. But, there was a timing ``fuse`` that would eliminate this central part and open up the comers atmore » « less
DOI: https://doi.org/10.2172/10169930

Full Text Available
Selective protection of poly(tetra-fluoroethylene) from effects of chemical etching

Patent Martinez, Robert J [Albuquerque, NM]; Rye, Robert R [Albuquerque, NM]

A photolithographic method for treating an article formed of polymeric material comprises subjecting portions of a surface of the polymeric article to ionizing radiation; and then subjecting the surface to chemical etching. The ionizing radiation treatment according to the present invention minimizes the effect of the subseuent chemical etching treatment. Thus, selective protection from the effects of chemical etching can be easily provided. The present invention has particular applicability to articles formed of fluorocarbons, such as PTFE. The ionizing radiation employed in the method may comprise Mg(k.alpha.) X-rays or lower-energy electrons.
Full Text Available
MEMS packaging with etching and thinning of lid wafer to form lids and expose device wafer bond pads

Patent Chanchani, Rajen; Nordquist, Christopher; Olsson, Roy H; ...

In wafer-level packaging of microelectromechanical (MEMS) devices a lid wafer is bonded to a MEMS wafer in a predermined aligned relationship. Portions of the lid wafer are removed to separate the lid wafer into lid portions that respectively correspond in alignment with MEMS devices on the MEMS wafer, and to expose areas of the MEMS wafer that respectively contain sets of bond pads respectively coupled to the MEMS devices.
Full Text Available
Chemical method for producing smooth surfaces on silicon wafers

Patent Yu, Conrad [Antioch, CA]

An improved method for producing optically smooth surfaces in silicon wafers during wet chemical etching involves a pre-treatment rinse of the wafers before etching and a post-etching rinse. The pre-treatment with an organic solvent provides a well-wetted surface that ensures uniform mass transfer during etching, which results in optically smooth surfaces. The post-etching treatment with an acetic acid solution stops the etching instantly, preventing any uneven etching that leads to surface roughness. This method can be used to etch silicon surfaces to a depth of 200 .mu.m or more, while the finished surfaces have a surface roughness of only 15-50more » .ANG. (RMS). « less
Full Text Available

Similar Records

Title: Method for protecting chip corners in wet chemical etching of wafers

Abstract

Citation Formats

Silicon as a mechanical material journal, May 1982

Fabrication of Non‐Underetched Convex Corners in Anisotropic Etching of (100)‐Silicon in Aqueous KOH with Respect to Novel Micromechanic Elements journal, December 1990

Mesa structure formation using potassium hydroxide and ethylene diamine based etchants conference, January 1988

Corner compensation techniques in anisotropic etching of conference, January 1991

Compensating corner undercutting in anisotropic etching of (100) silicon journal, June 1989

Silicon as a mechanical material
journal, May 1982

Fabrication of Non‐Underetched Convex Corners in Anisotropic Etching of (100)‐Silicon in Aqueous KOH with Respect to Novel Micromechanic Elements
journal, December 1990

Mesa structure formation using potassium hydroxide and ethylene diamine based etchants
conference, January 1988

Corner compensation techniques in anisotropic etching of
conference, January 1991

Compensating corner undercutting in anisotropic etching of (100) silicon
journal, June 1989