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:
Jul. 24, 2007
Filed:
Jan. 21, 2005
Hisatsugu Kurita, Niigata, JP;
Masato Igarashi, Niigata, JP;
Takeshi Senda, Niigata, JP;
Koji Izunome, Niigata, JP;
Hisatsugu Kurita, Niigata, JP;
Masato Igarashi, Niigata, JP;
Takeshi Senda, Niigata, JP;
Koji Izunome, Niigata, JP;
Toshiba Ceramics Co., Ltd., Tokyo, JP;
Abstract
A method for manufacturing a strained silicon wafer, having steps of a first step of preparing a single crystal silicon substrate, a second step of forming a graded SiGe layer on the substrate, the graded SiGe layer having a first Ge composition ratio increased stepwisely from 5 to 60% at atomic ratio, a third step of forming a SiGe constant composition layer on the graded SiGe layer, the SiGe constant composition layer having a Ge composition ratio substantially equal to the Ge composition ratio on a surface of the-graded SiGe layer and a fourth step of forming a strained Si layer on the SiGe constant composition layer. The second through fourth steps are performed under the reduced pressure atmosphere while the single crystal silicon substrate is rotated in a circumferential direction at a rate from 300 rpm to 1500 rpm.