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:
Sep. 29, 1992
Filed:
Oct. 11, 1991
Applicant:
Inventors:
Toshiya Watanabe, Kanagawa, JP;
Tetsuo Kitabayashi, Kanagawa, JP;
Assignee:
Toto Ltd., Fukuoka, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02N / ;
U.S. Cl.
CPC ...
361234 ; 279128 ;
Abstract
An electrostatic chuck for electrostatically attracting and holding an object such as a semiconductor wafer includes a base plate, at least two layers each including an electrically insulating film and an electrode attached to a lower surface thereof, the at least two layers being disposed as attractive layers on the base plate, and a voltage applying assembly for selectively applying a voltage to at least one of the electrodes to electrostatically attract the object to the insulating film of an uppermost one of the layers. The insulating films may have different insulation resistances to allow for a wider range of temperature changes.