Lateral device structures using self-aligned fabrication techniques

Claim 1

A process for forming a semiconductor device of tightly controlled width, comprising the steps of: providing a body of a first conductivity type semiconductive material; providing a first insulating layer on said semiconductive material; providing a first layer of material over one portion of said insulating layer leaving another portion of said insulation layer exposed said first layer having a substantially vertical surface extending between said one and another portions; providing a second layer of material conformally over said first layer of material and said exposed insulating layer; anisotropically etching said conformal second layer of material forming a stud of said second material abutting said vertical surface of said first layer of material with the width of said stud defined by the thickness of said conformal second layer of material; removing said first layer of material; forming a protrusion of said semiconductive material on a pedestal thereof with the width of said protrusion defined by the width of said stud and said protrusion having opposing vertical sidewalls by anisotropically etching said first insulating layer and said body of semiconductive material surrounding said stud using said stud as a mask; forming an oxidation-resistant insulator layer on said vertical sidewalls and on the semiconductor material surrounding said protrusion; etching to recess said semiconductor material not masked by said oxidation-resistant layer; forming dielectric isolation in said recess by thermal oxidation thereof; selectively etching said oxidation-resistant layer to form localized contact openings therein; and making electrical contact via said openings to opposing vertical sidewalls of said protrusion of semiconductive material; whereby a semiconductor device of tightly controlled width protruding from said body is formed.