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:
Aug. 14, 2012
Filed:
Nov. 24, 2010
Keiji Ishibashi, Itami, JP;
Fumitake Nakanishi, Itami, JP;
Keiji Ishibashi, Itami, JP;
Fumitake Nakanishi, Itami, JP;
Sumitomo Electric Industries, Ltd., Osaka-shi, Osaka, JP;
Abstract
A compound semiconductor substrateaccording to the present invention is comprised of a Group III nitride and has a surface layercontaining a chloride of not less than 200×10atoms/cmand not more than 12000×10atoms/cmin terms of Cl and an oxide of not less than 3.0 at % and not more than 15.0 at % in terms of O, at a surface. The inventors conducted elaborate research and newly discovered that when the surface layerat the surface of the compound semiconductor substratecontained the chloride of not less than 200×10atoms/cmand not more than 12000×10atoms/cmin terms of Cl and the oxide of not less than 3.0 at % and not more than 15.0 at % in terms of O, Si was reduced at an interface between the compound semiconductor substrateand an epitaxial layerformed thereon and, as a result, the electric resistance at the interface was reduced.