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. 20, 1999
Filed:
Sep. 30, 1997
Fumio Sakai, Utsunomiya, JP;
Kazuhito Outsuka, Tokyo, JP;
Yuichi Yamada, Utsunomiya, JP;
Kazuhiro Takahashi, Utsunomiya, JP;
Yasuo Hasegawa, Utsunomiya, JP;
Hideki Nogawa, Utsunomiya, JP;
Shinji Utamura, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A projection exposure apparatus including a projection optical system for projecting a pattern of a reticle onto a substrate, an optical characteristic detecting device for detecting a change in optical characteristic of the projection optical system, which change may result from the projection of the reticle pattern onto the substrate through the projection optical system, and a light detecting device for detecting at least one of (i) an intensity distribution of light from the reticle pattern, at a position adjacent to the reticle or adjacent to an imaging plane on which the reticle is to be imaged, and (ii) an intensity distribution of the light from the reticle pattern, at a position adjacent to a pupil plane of the projection optical system, wherein the optical characteristic detecting device is arranged to detect the amount of change in optical characteristic in accordance with the intensity distribution detected by the light detecting device.