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:
Aug. 28, 2001
Filed:
Mar. 29, 2000
Hiroyuki Watanabe, Takefu, JP;
Hiroyuki Miyazawa, Koriyama, JP;
Tatsuhiro Sato, Koriyama, JP;
Satoshi Soeta, Takefu, JP;
Tetsuya Igarashi, Takefu, JP;
Other;
Abstract
There is provided a quartz glass crucible for pulling a silicon single crystal and a production process for the crucible, wherein an inner surface of the crucible is crystallized without addition of impurities during pulling a silicon single crystal, thereby impurities serving as causes of crystal defects being not incorporated into the silicon single crystal, so that deterioration of its inner surface is suppressed to improve a crystallization ratio, and accordingly productivity of the quartz glass crucible as well as a quality of the silicon single crystal is improved, and the quartz glass crucible for pulling a silicon single crystal comprises a crucible base body (,) made of a translucent quartz glass layer and a synthetic quartz glass layer (,) formed on an inner wall surface of the crucible base body (,), wherein a portion encircled by a brown ring on an inner surface of the quartz glass crucible is uniformly crystallized during pulling the silicon single crystal.