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. 10, 1983
Filed:
Aug. 07, 1981
Nobuo Kawase, Sagamihara, JP;
Masayoshi Aigo, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A quartz tube adapted for thermal processing of semiconductor substrates comprising a double-layered central tube having an external sintered crystalline quartz layer fused with a quartz layer of different quality, i.e. an internal transparent fused quartz layer. Both ends of the central tube are fused with the ends of two transparent fused quartz end tubes. The double-layered tube portion can be produced by compacting quartz particulates by means of centrifugal force within a mould and heating from the center with or without placing a fused quartz tube on its inner surface. Semiconductor substrates are processed using this quartz tube, thereby semiconductor devices having stabilized high qualities are produced at an increased yield as well as at a low cost.