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:
Nov. 17, 2009
Filed:
Oct. 09, 2007
Takayuki Nishiura, Itami, JP;
Yoshio Mezaki, Itami, JP;
Yusuke Horie, Itami, JP;
Yasuaki Higuchi, Itami, JP;
Takayuki Nishiura, Itami, JP;
Yoshio Mezaki, Itami, JP;
Yusuke Horie, Itami, JP;
Yasuaki Higuchi, Itami, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A GaAs semiconductor substrate includes a surface layer. When an atomic ratio is to be calculated using a 3d electron spectrum of Ga atoms and As atoms measured at the condition of 10° for the photoelectron take-off angle θ by X-ray photoelectron spectroscopy, the structural atomic ratio of all Ga atoms to all As atoms (Ga)/(As) at the surface layer is at least 0.5 and not more than 0.9, the ratio of As atoms bound with O atoms to all Ga atoms and all As atoms (As—O)/{(Ga)+(As)} at the surface layer is at least 0.15 and not more than 0.35, and the ratio of Ga atoms bound with O atoms to all Ga atoms and all As atoms (Ga—O)/{(Ga)+(As)} at the surface layer is at least 0.15 and not more than 0.35. Accordingly, there is provided a GaAs semiconductor substrate having a surface cleaned to an extent allowing removal of impurities and oxides at the surface by at least thermal cleaning of the substrate.