Encapsulation method for localized oxidation of silicon

US4927780A · kind A · utility

Assignee

• Motorola, Inc. · US

Inventors

• Scott S. Roth · Austin, US
• Bich-Yen Nguyen · Austin, US
• Philip J. Tobin · Austin, US
• Wayne J. Ray · Austin, US
• E. Petyr Wachholz · Cedar Park, US
• Glenn Wissen · Elgin, US

Key dates

• Filing date: Oct 2, 1989
• Grant date: May 22, 1990
• Expiry date: Oct 2, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/7621
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

An improved LOCOS isolation process is disclosed wherein an oxidizable layer is conformably dieposited to overlie a silicon nitride oxidation mask. In accordance with one embodiment of the invention, a composite layer comprising a buffer layer and an oxidation resistant material is patterned to form an oxidation mask on a silicon substrate. A layer of an oxidizable material is conformably deposited to overlie the oxidation mask. During the oxidation process used to form electrical isolation structures in the substrate, a substantial reduction in lateral oxidation encroachment is realized.