Semiconductor etching process which produces oriented sloped walls

Claim 1

A method of forming a semiconductor device including performing a dry plasma etch at one major surface of a monocrystalline silicon substrate to form a constant sloped lateral wall intersecting said one major surface comprising selectively protecting a portion of said major surface, positioning said substrate on one of two spaced electrodes, providing a gaseous atmosphere between said electrodes, and establishing an electric field between said electrodes capable of creating a plasma in said gaseous atmosphere, characterized in that said sloped lateral wall is oriented along a selected crystallographic plane of said monocrystalline silicon substrate by introducing into contact with said major surface at unprotected locations a chlorofluorocarbon gas which, when formed into a plasma crystallographically etches monocrystalline silicon and employing during etching a pressure of at least 6.67 Pa and a radio frequency power density of less than 3 watts per square centimeter.

Claim 2

A method of forming a semiconductor device including performing a dry plasma etch at one major surface of a monocrystalline silicon substrate to form a constant sloped lateral wall intersecting said one major surface comprising selectively protecting a portion of said major surface, positioning said substrate on one of two spaced electrodes, providing a gaseous atmosphere between said electrodes, and establishing an electric field between said electrodes capable of creating a plasma in said gaseous atmosphere, characterized in that said sloped lateral wall is oriented along a selected crystallographic plane of said monocrystalline silicon substrate by introducing into contact with said major surface at unprotected locations a chlorofluorocarbon gas which, when formed into a plasma crystallographically etches monocrystalline silicon and employing during etching a pressure of at least 6.67 Pa and a radio frequency power density of less than 3 watts per square centimeter.