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:
Jul. 17, 2018
Filed:
Oct. 13, 2017
Sumco Corporation, Minato-ku, Tokyo, JP;
Toshiaki Sudo, Akita, JP;
Tadahiro Sato, Akita, JP;
Ken Kitahara, Akita, JP;
Eriko Kitahara, Akita, JP;
SUMCO CORPORATION, Tokyo, JP;
Abstract
A vitreous silica crucible used to pull up silicon single crystal includes: a cylindrical straight body portion, a corner portion formed at a lower end of the straight body portion, and a bottom portion connected with the straight body portion via the corner portion, wherein the vitreous silica crucible further comprises: an opaque outer layer enclosing bubbles therein; and a transparent inner layer from which bubbles are removed, wherein the residual distortion's distribution obtained by measuring the silica glass's inner surface in a non-destructed state has an optical path difference which is 130 nm or less, which residual distortion's distribution is measured using a distortion-measuring apparatus which converts a linearly polarized light into circularly polarized light and then irradiates the crucible's wall.