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. 22, 1992
Filed:
Sep. 05, 1991
Junji Isohata, Tokyo, JP;
Shinji Tsutsui, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An exposure apparatus for exposing an exposure member or wafer to a pattern with radiation in a step-and-repeat manner thereby to transfer images of the pattern onto different regions on a surface of the exposure member. The apparatus includes an XY stage for moving the wafer in X- and Y-directions, a .theta. stage for moving the wafer in a rotational direction relative to the XY stage, laser interferometers for measuring an amount of movement of the wafer by the XY stage, in each of the X- and Y-directions, by use of a mirror member mounted on the .theta. stage, and a carriage for carrying the XY and .theta. stages and a portion of the interferometers to move the wafer relative to an exposing system for effecting the scan-exposure on the region of the wafer. The mirror member is placed on the .theta. stage, and another portion of the interferometers is mounted on a fixed system independent of the carriage. The inclination of the mirror member is detected at any desired time by moving the carriage and calculating the inclination from the amount of movement of the carriage and the amount of displacement of the mirror member measured by the interferometer mounted on the fixed system. Based on the thus detected inclination of the mirror member, the inclination is corrected and the stepwise movement of the XY stage can be performed with a higher accuracy, so that the transfer accuracy between the pattern images printed on the wafer in the case of the step-and-repeat exposure can be highly improved.