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:
Mar. 07, 1995
Filed:
Jun. 17, 1993
Masanori Kobayashi, Kawasaki, JP;
Ken Yamazaki, Kawasaki, JP;
Tsutomu Ogawa, Kawasaki, JP;
Yoshiko Okui, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
In a apparatus made of silica such as a heating furnace, a wafer basket, stick or the like used for semiconductor device fabrication, a first silica layer on the side faced to a semiconductor wafer contains a large amount of the OH group, and a second silica layer on the opposed side contains a small amount of the OH group. With this structure, it is possible to reduce the amount of impurities released through the first silica layer, and to suppress the deformation of the apparatus by the second silica layer. Also, by holding a third silica layer between the first and second silica layers, it is possible to further reduce the amount of impurities released from the first silica layer.