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:
Dec. 13, 2011
Filed:
Jul. 04, 2007
Satoshi Oka, Annaka, JP;
Nobuhiko Noto, Annaka, JP;
Satoshi Oka, Annaka, JP;
Nobuhiko Noto, Annaka, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
The present invention is a method for producing a semiconductor substrate, including steps of forming a SiGe gradient composition layer and a SiGe constant composition layer on a Si single crystal substrate, flattening a surface of the SiGe constant composition layer, removing a natural oxide film on the flattened surface of the SiGe constant composition layer, and forming a strained Si layer on the surface of the SiGe constant composition layer from which the natural oxide film has been removed, wherein the formation of the SiGe gradient composition layer and the formation of the SiGe constant composition layer are performed at a temperature Tthat is higher than 800° C., the removal of the natural oxide film from the surface of the SiGe constant composition layer is performed in a reducing atmosphere through a heat treatment at a temperature Tthat is equal to or higher than 800° C. and lower than the temperature T, and the formation of the strained Si layer is performed at a temperature Tthat is lower than the temperature T. This method enables epitaxial growth of the strained Si layer on the flattened SiGe layer without degrading surface flatness of the SiGe layer.