Self-alignment technique for forming junction isolation and wells

US5556796A · kind A · utility

Assignee

• Micrel, Inc. · US

Inventors

• Martin E. Garnett · Los Gatos, US
• Michael Hsing · Saratoga, US

Key dates

• Filing date: Apr 25, 1995
• Grant date: Sep 17, 1996
• Expiry date: Apr 25, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S148/009

Abstract

A method in accordance with one embodiment of the present invention may be used to self-align isolation regions, sinkers, and wells. In this improved method, P+ isolation regions, N+ sinkers, and P-wells are defined using the same masking step used to define the N-wells. The use of a single masking step to initially define the P+ isolation regions, N+ sinkers, N-wells, and P-wells results in the self-alignment of these regions. Several critical mask alignments are thereby eliminated, thus avoiding/simplifying fabrication steps, conserving die area, and allowing increased component density.