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:
Aug. 22, 2000
Filed:
Sep. 30, 1998
Hiroyuki Watanabe, Takefu, JP;
Tatsuhiro Sato, Takefu, JP;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Shin-Etsu Quartz Products Co., Ltd., Tokyo, JP;
Abstract
A method for producing an improved quartz glass crucible for pulling up silicon single crystals comprises forming a premolding by feeding powdered silicon dioxide into the mold and by then forming it into a layer along the inner surface of the mold; forming a crucible base body of a translucent quartz layer by heating the premolding from the inner side, thereby partially melting the powdered silicon dioxide, followed by cooling and solidifying the melt; forming a crystallization-promoter containing layer along the internal wall surface of the crucible body by scattering the crystallization promoter on the surface of the internal wall of the crucible body during or after forming the crucible base body; and forming a synthetic quartz glass inner layer by scattering and fusing a powder of silicon dioxide on the crystallization promoter-containing layer that is formed along the internal wall surface of the crucible base body.