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:
Jul. 28, 1992
Filed:
Jan. 29, 1991
Hidehiko Fujioka, Atsugi, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Disclosed is a method of exposure control for use in a step-and-repeat type exposure apparatus that includes a radiation source for emitting a radiation beam and a workpiece holding chuck having an attracting surface. The method includes placing a first workpiece on the attracting surface of the holding chuck so that the workpiece is attracted to and held by the holding chuck, moving the holding chuck stepwise so that different portions of the workpiece are sequentially brought to an exposure station and exposing that portion of the first workpiece placed at the exposure position, detecting the temperature of the attracting surface of the holding chuck each time a portion of the first workpiece is exposed, memorizing data related to the detected temperature, removing the first workpiece from the holding chuck and placing a second workpiece on the attracting surface of the holding chuck, moving the holding chuck, bearing the second workpiece, stepwise for exposure of different portions of the second workpiece and adjusting the temperature of the attracting surface of the holding chuck each time a portion of the second workpiece is brought to the exposure position, in accordance with the memorized data.