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.

Date of Patent:
Mar. 30, 2010

Filed:

Jul. 30, 2003
Applicants:

Yasuo Ohama, Takefu, JP;

Takayuki Togawa, Takefu, JP;

Inventors:

Yasuo Ohama, Takefu, JP;

Takayuki Togawa, Takefu, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B 15/10 (2006.01); F27B 14/10 (2006.01); C03B 11/00 (2006.01); C03B 15/00 (2006.01); C03B 19/01 (2006.01);
U.S. Cl.
CPC ...
Abstract

An object of the invention is to provide a quartz glass crucible reduced in the generation of vibration occurring on the surface of a silicon melt and free from the generation of rough surface and cristobalite spots, yet capable of pulling up single crystal silicon stably and at high yield even in long-term operations; it is also an object to provide a method for producing the same. In a quartz glass crucible for pulling up single crystal silicon comprising a crucible base body having a bottom part and a straight shell part with an inner layer provided to the inner surface thereof, the quartz glass crucible is characterized by that said inner layer comprises a synthetic quartz glass layer from the lowest end to at least a height of 0.25 H; a naturally occurring quartz glass layer or a mixed layer of naturally occurring quartz glass and synthetic quartz glass extended in a range of from at least 0.5 H to 0.8 H; and one selected from a synthetic quartz glass layer, a naturally occurring quartz glass layer, and a mixed quartz glass layer of naturally and synthetic quartz glass for the rest of the inner layer; wherein H represents the height from the lowest end of the bottom part to the upper end plane of the shell part. It also provides a method for producing the quartz glass crucible above.


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