US PATENT SUBCLASS 438 / FOR 128
.~.~ Differential etching of a substrate (156/654.1)

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use


438 /   HD   SEMICONDUCTOR DEVICE MANUFACTURING: PROCESS

983  DF  ZENER DIODES {1}
FOR 100  DF  .~ Etching of semiconductor precursor, substrates, and devices used in an electrical function (156/625.1) {17}
FOR 128.~.~ Differential etching of a substrate (156/654.1) {2}
FOR 129  DF  .~.~.~> Composite substrate (156/655.1) {2}
FOR 132  DF  .~.~.~> Resist coating (156/659.11) {1}

DEFINITION

Classification: 438/FOR.128

Differential etching of a substrate:

Foreign art collection for processes directed to (a) contacting only selected surface areas of the substrate with the etchant to remove a constituent part of the substrate at the selected surface areas only, or (b) cause the substrate to be treated at different rates in different areas to produce a nonuniform surface.