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:
May. 19, 1998
Filed:
Apr. 19, 1996
Mitsuya Sato, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A scan type exposure apparatus includes a first movable stage for carrying a reticle thereon and a second movable stage for carrying a wafer thereon, a projection system for projecting a pattern of the reticle onto the wafer through a projection optical system while scanningly moving the first and second movable stages in a timed relation, relative to the projection optical system, a first mark formed on the reticle and including a plurality of marks arrayed along a scan direction, a reference plate fixedly mounted on the second movable stage and having a second mark including a plurality of marks arrayed along the scan direction, a third movable stage for carrying the second movable stage thereon and being movable in a direction different from the movement direction of the second stage, and a photodetector fixedly mounted on the third movable stage. The second and third movable stages are moved so as to place the reference plate and the photodetector at a position of an image of the first mark as projected by the projection optical system, and the image of the first mark is detected through the second mark by using the photodetector while moving the first and second movable stages in a timed relation, relative to the projection optical system.