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. 16, 2001
Filed:
Sep. 28, 2000
Applicant:
Inventors:
Makoto Ito, Saga, JP;
Hiroki Murakami, Saga, JP;
Assignee:
Sumitomo Metal Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B 1/500 ;
U.S. Cl.
CPC ...
C30B 1/500 ;
Abstract
An inner surface of a quartz crucible after being used is cleaned by an acid liquid, and an extraneous material adhered to its inner surface is removed. The inner surface after the extraneous material has been removed is heat treated at 1600° C. or more, and the inner surface where cristobalite formation occurs is recovered into an amorphous state. In this manner, the quartz crucible after being used for growing single crystal silicon is reproduced to a level equal to a new crucible.