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, 2018
Filed:
May. 30, 2014
Nippon Steel & Sumikin Materials Co., Ltd., Saitama, JP;
Kiyoshi Kojima, Saitama, JP;
Masashi Nakabayashi, Saitama, JP;
Kota Shimomura, Saitama, JP;
Yukio Nagahata, Saitama, JP;
SHOWA DENKO K.K., Tokyo, JP;
Abstract
Provided are a method of evaluating an internal stress of a silicon carbide (SiC) single crystal wafer and a method of predicting warpage of the SiC single crystal wafer after completion of polishing by evaluating the internal stress of the wafer. Wavenumber shift amounts of Raman-scattered light are measured at two points within a surface of the SiC single crystal wafer, and the internal stress is evaluated through use of a difference between the wavenumber shift amounts. Also provided is a method of predicting warpage of a silicon carbide single crystal wafer in advance, the silicon carbide single crystal wafer being produced by sublimation-recrystallization method, the method including predicting warpage of a SiC single crystal wafer through use of the evaluation indicator.