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:
May. 21, 1991
Filed:
Aug. 27, 1990
Fujitsu Limited, Kawasaki, JP;
Abstract
In a direct bonded SOI substrate where the SiO.sub.2 films OA, OB are respectively provided on the single surfaces of the silicon substrates A, B, at least any one of SiO.sub.2 films OA, OB has thickness of 1 .mu.m or more. These SiO.sub.2 films OA, OB are bonded and moreover the one silicon substrate B of such a bonded substrate is ground to thickness of about 1 .mu.m. A semiconductor device having a trench structure wherein the trench formed on the silicon substrate B passes through the interface between the SiO.sub.2 film OB and the SiO.sub.2 film OA. The bottom of such a trench is located within the SiO.sub.2 film OA and the bottom of the polycrystalline silicon conductive film within the trench is located within the SiO.sub.2 film OA rather than the interface between the silicon substrate B and SiO.sub.2 film OB.