Method of making an article comprising a buried SiO.sub.2 layer

US4749660A · kind A · utility

Assignee

• American Telephone and Telegraph Company, AT&T Bell Laboratories · US

Inventors

• Kenneth T. Short · New Providence, US
• Alice E. White · Brookline, US

Key dates

• Filing date: Nov 26, 1986
• Grant date: Jun 7, 1988
• Expiry date: Nov 26, 2006

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76283
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

We have discovered that high quality subcritical SIMOX silicon-on-insulator wafers can be produced by a method that comprises a randomizing implant followed by an appropriate heat treatment. In a preferred embodiment, the inventive method comprises, in succession, a subcritical oxygen implant (nominal wafer temperature <350.degree. C.) into a (100) Si wafer, a low temperature (500.degree.-700.degree. C.) anneal, a high temperature (>1200.degree. C.) anneal, a randomizing implant (.about.5.times.10.sup.14 Si/cm.sup.2, nominal wafer temperature <100.degree. C.), and a low temperature anneal (nominal wafer temperature between 500.degree. and 700.degree. C.). The resulting buried SiO.sub.2 layer typically is relatively thin (e.g., 60 nm), stoichiometric, continuous, and essentially free of Si inclusions, and the Si overlayer typically is of device quality and essentially free of twins, with .chi.min.about.3%.