The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 23, 1998
Filed:
Oct. 15, 1996
Komatsu Electronic Metals Co., Ltd., Kanagawa, JP;
Abstract
The present invention, a silicon-on-insulator (SOI) substrate and its fabrication method, is suited to the wafer-bonding method. A pre-oxidation treatment accompanying the oxidation treatment and the adhesive thermal treatment to prevent metal impurities from polluting semiconductor wafers. Before an oxide layer is thermally grown on one wafer or after two bonded wafers are subjected to a adhesive thermal treatment at a temperature T1, the pre-oxidation treatment is performed at a temperature of T2, which satisfies the relation equation of T1-300.ltoreq.T2.ltoreq.T1-100 (.degree.C.). Water steam, pure oxygen, or diluted oxygen, is conducted into the furnace, in which the pre-oxidation treatment is performed in an oxidation ambient. Accordingly, an oxide film having a predetermined thickness is formed on the surface of the SOI substrate serving as a barrier for preventing metal impurities, such as Fe, Cr, or the like, from invading the substrate and degrading the electrical characteristics thereof.