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. 31, 1994
Filed:
Dec. 16, 1992
Reiji Niino, Kofu, JP;
Isao Siratani, Sagamihara, JP;
Yutaka Simada, Sagamihara, JP;
Hiroki Fukusima, Sagamihara, JP;
Hirofumi Kitayama, Kanagawa, JP;
Akimichi Yonekura, Kawasaki, JP;
Yuuichi Mikata, Kawasaki, JP;
Tokyo Electron Limited, Tokyo, JP;
Tokyo Electron Sagami Limited, Kanagawa, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A semiconductor wafer boat used in a vertical CVD apparatus includes four columns fixed to upper and lower support plates. Each of the columns has a plurality of first grooves arranged at regular intervals in the vertical direction so as to place wafers in substantially parallel to each other, and a plurality of second grooves formed alternately with the first grooves. A plate ring is provided for each of the second grooves so as to improve the uniformity of thickness of a film to be formed on each wafer. Each ring has an outer diameter larger than that of a wafer, and an inner diameter smaller than that of the wafer. Each ring is placed such that there is a clearance for transferring each wafer between each ring and each wafer in the vertical direction.