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:
Jun. 07, 2011
Filed:
Mar. 04, 2010
Yoshiyuki Tsuji, Akita, JP;
Toshio Tsujimoto, Akita, JP;
Yoshiyuki Tsuji, Akita, JP;
Toshio Tsujimoto, Akita, JP;
Japan Super Quartz Corporation, Tokyo, JP;
Abstract
A silica glass crucible used for pulling up silicon single crystal at a high temperature. The silica glass crucible may have at least an outer surface of a wall part of the crucible covered with fine grooves having a length of less than 200 μm, a width of less than 30 μm and a depth of from more than 3 μm to less than 30 μm. The fine groves may be formed by carrying out a sand-blast treatment and a hydrofluoric acid etching and may exist on more than 10% of the outer surface of the crucible, and a sliding frictional coefficient of the outer surface of the crucible to a carbon at 1500° C. is more than 0.6.