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. 29, 1992
Filed:
Jun. 19, 1991
Applicant:
Inventors:
Mitsuo Matsumura, Takefu, JP;
Hiroshi Matsui, Takefu, JP;
Assignee:
Shin-Etsu Quartz Products Co. Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03C / ; C03B / ; C03B / ;
U.S. Cl.
CPC ...
65 181 ; 65 608 ; 65 71 ; 65144 ; 65900 ;
Abstract
A quartz glass crucible for use in a process for pulling a single crystal silicon and having an outer layer and an inner layer. The outer layer contains less than 0.3 ppm each of Na, K and Li and more thant 5 ppm of Al. The outer layer further contains bubbles to present an opaque appearance. The inner layer is made by melting powders of high purity non-crystalline synthetic silica and contains less then 200 ppm of OH group. There is also disclosed a method for producing the crucible.