Total dielectric isolation for integrated circuits

US4502913A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• John S. Lechaton · Wappingers Falls, US
• Shashi D. Malaviya · Hopewell Junction, US
• Dominic J. Schepis · Wappingers Falls, US
• Gurumakonda R. Srinivasan · Poughkeepsie, US

Key dates

• Filing date: Jun 30, 1982
• Grant date: Mar 5, 1985
• Expiry date: Jun 30, 2002

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/763
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A fully isolated dielectric structure for isolating regions of monocrystalline silicon from one another and method for making such structure are described. The structure uses a combination of recessed oxide isolation with pairs of parallel, anisotropic etched trenches which are subsequently oxidized and filled to give complete dielectric isolation for regions of monocrystalline silicon. The anisotropic etching preferably etches a buried N+ sublayer under the monocrystalline silicon region and then the trench structure is thermally oxidized to consume the remaining N+ layer under the monocrystalline region and to fully isolate the monocrystalline silicon region between pairs of such trenches.