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:
Oct. 20, 2015
Filed:
Aug. 02, 2012
Fumiaki Maruyama, Gunma-gun, JP;
Naoki Naito, Nishishirakawa-gu, JP;
Atsuo Uchiyama, Kosyoku, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
Provided is a silicon wafer which is stabilized in quality exerting no adverse influence on device characteristics and manufactured by restricting a boron contamination from the environment, and a manufacturing process therefor. Concretely, the silicon wafer is characterized by an attached boron amount thereon being 1×10atoms/cmor less. In order to manufacture such a wafer as contains a small amount of boron attached on the wafer surface, the wafer is treated in an atmosphere of boron concentration of 15 ng/mor less. Boron-less filters and boron adsorbing filters are used as filters in a clean room and the like so as to lower the boron concentration in the atmosphere.