skip to main content
DOE Patents title logo U.S. Department of Energy
Office of Scientific and Technical Information

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:
 [1]
  1. Campbell, CA
Issue Date:
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
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.
Hui, Wing C. Method for protecting chip corners in wet chemical etching of wafers. United States.
Hui, Wing C. Sat . "Method for protecting chip corners in wet chemical etching of wafers". United States. https://www.osti.gov/servlets/purl/869158.
@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}
}

Patent:

Save / Share:

Works referenced in this record:

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