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. 07, 2010
Filed:
Oct. 26, 2007
Yasuo Koike, Tokyo, JP;
Yasuo Koike, Tokyo, JP;
Sumco Corporation, Tokyo, JP;
Abstract
The present invention can provide a silicon semiconductor substrate used for and epitaxial wafer, in which uniform and high-level gettering ability is obtained irrespective of slicing positions from a silicon single crystal while generation of epitaxial defects can be suppressed, by doping carbon or carbon along with nitrogen during a pulling process of a CZ method or by performing appropriate heat treatment prior to the epitaxial process. Therefore, a crystal production yield can remarkably be improved because a permissible upper limit (concentration margin) of an oxygen concentration which is restricted by formation of a ring-shaped OSF region can be higher and also an excellent gettering ability is exhibited, while allowing an epitaxial wafer to be produced wherein epitaxial defects attributable to substrate crystal defects are not formed.