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:
Oct. 08, 1991
Filed:
Feb. 26, 1991
Tokyo Electron Sagami Limited, Kanagawa, JP;
Abstract
A wafer boats supporting wafers is loaded into and unloaded from a reaction tube with a lid therebelow in a vertical heat treatment apparatus, while holding the wafer boat vertical with respect to the lid. An arm is provided in a space below the reaction tube, for transferring wafer boats along a path, while holding the wafer boats vertical and in a substantially horizontal plane. Three stations are formed in the path. At the first station, unprocessed wafers are mounted on a first wafer boat located, while wafers mounted on a first wafer boat is being heat-treated in said reaction tube. Then, the first wafer boat is transferred from the first station to the third station, and is held at the third station. While the first wafer boat is held at the third station, the second wafer boat is lowered to the second station to unload the second wafer boat from the reaction tube, and then is transferred to the first station. Thereafter, the heat-treated wafers are removed from the second wafer boat located at the first station. Next, the first wafer boat is transferred from the third station to the second station, while the second wafer boat is located at the first station, and then is mounted onto the lid, thereby to load the first wafer boat into the reaction tube.