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. 28, 2013
Filed:
Apr. 27, 2009
Masanori Fukui, Akita, JP;
Hiroshi Kishi, Akita, JP;
Masanori Fukui, Akita, JP;
Hiroshi Kishi, Akita, JP;
Japan Super Quartz Corporation, Akita, JP;
Abstract
A silica glass crucible having a sidewall portion and a bottom portion is provided with a first synthetic silica glass layer constituting an inner layer at least in the sidewall portion, a second synthetic silica glass layer constituting an inner layer at least in a region including a center of the bottom portion, and a natural silica glass layer constituting an outer layer in the sidewall portion and the bottom portion. A melting rate of the second synthetic silica glass layer with respect to a silicon melt is higher than that of the first synthetic silica glass layer. An aluminum concentration of the second synthetic silica glass layer is higher than that of the first synthetic silica glass layer.