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:
May. 03, 2005
Filed:
May. 31, 2001
Yasuo Ohama, Takefu, JP;
Shigeo Mizuno, Takefu, JP;
Yasuo Ohama, Takefu, JP;
Shigeo Mizuno, Takefu, JP;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Shin-Etsu Quartz Products Co. Ltd., Tokyo, JP;
Abstract
Problems the invention is to solve: An object of the present invention is to provide a method for producing a quartz glass crucible capable of pulling up a silicon single crystal at a highly improved yield, yet without generating oscillation at the surface of the melt on pulling up silicon single crystal, and free from generating dislocations due to the peeling off of quartz glass fractions. Means for solving the problems: In a method for producing a quartz glass comprising a step of forming a base body comprising supplying a powder of silicon dioxide inside a rotating mold and thereby obtaining a molded body in the shape of a crucible by taking advantage of the centrifugal force, followed by heating and fusing the resulting molded body to obtain a translucent quartz glass crucible base body, and a step of forming an inner layer by newly supplying a powder of silicon dioxide into the heated atmosphere inside said crucible base body during or after forming said crucible base body, thereby forming an inner layer of a transparent quartz glass on the inner plane of said crucible base body, claimed is a method in which water vapor is introduced into said crucible base body in at least a part of the step for forming the inner layer.