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:
Jan. 19, 2021
Filed:
Mar. 23, 2018
Sumitomo Heavy Industries Ion Technology Co., Ltd., Tokyo, JP;
Abstract
A wafer holding device includes a wafer chuck that includes a wafer holding surface coming into contact with a wafer to be held and a plurality of attraction regions provided on the wafer holding surface, and a controller configured to independently control an attraction force of an at least one of the plurality of attraction regions. In a case where fixing of the wafer is released, the controller establishes a temporarily fixing state in which the attraction force of the at least one of the plurality of attraction regions is smaller than an attraction force in fixing the wafer, and thereafter, the controller sets attraction forces of all of the plurality of attraction regions to be smaller than the attraction force in fixing the wafer.