Method to reduce stress from trench structure on SOI wafer

US5470781A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Dureseti Chidambarrao · Weston, US
• Louis L. Hsu · Fishkill, US
• J. Daniel Mis · Cary, US
• James Peng · Pechhofer Weg, US

Key dates

• Filing date: Dec 14, 1993
• Grant date: Nov 28, 1995
• Expiry date: Dec 14, 2013

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76286
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

In an isolation trench in a silicon-on-insulator wafer, the sidewalls of the trench curve outwardly at the bottom of the trench where the top silicon layer meets the underlying oxide insulating layer. This sidewall geometry eliminates the sharp corner at the bottom of the trench. Preferably, the top edge of the trench wall is also curved.