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:
Mar. 16, 1999
Filed:
Aug. 06, 1996
Kenji Nishi, Kanagawa-ken, JP;
Kazuo Ushida, Tokyo, JP;
Seiro Murakami, Chiba-ken, JP;
Tohru Kiuchi, Tokyo, JP;
Yasuaki Tanaka, Kanagawa-ken, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A projection optical system of a projection exposure apparatus according to the present invention has a plurality of optical members made of glass materials at least one of which has a temperature characteristic of index of refraction different from that of the other glass material. Further, a temperature control device for controlling a temperature of at least one of the optical members is provided. An imaging characteristic of the projection optical system is controlled. The imaging characteristic to be controlled is a non-linear magnification or curvature of field. The temperature control device sets the temperature to be controlled to a variable target temperature determined in accordance with the imaging characteristic of the projection optical system. An exposing operation for transferring a mask pattern to a photosensitive substrate is started after the temperature of the optical member to be controlled reaches a predetermined allowable range of the target temperature.