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:
Jun. 28, 1994
Filed:
Aug. 17, 1993
Kazuo Terada, Tokyo, JP;
Tokyo Electron Limited, Tokyo, JP;
Tokyo Electron Tohoku Limited, Esashi, JP;
Abstract
A system for supporting and rotating substrates in a process chamber comprising a first exhaust vacuum pump for exhausting the process chamber, a shaft vertically extending into the process chamber to support wafers in it, bearings for supporting the shaft rotatable, a mechanism for rotating the shaft together with the wafers, a bearing casing for covering the bearings and communicated with the process chamber, a second exhaust vacuum pump for exhausting the bearing casing, and a controller for controlling the first and second exhaust vacuum pumps in such a way that the bearing casing is exhausted by the second exhaust vacuum pump before the process chamber is exhausted by the first exhaust vacuum pump.