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. 02, 2002
Filed:
Oct. 18, 1999
Kenji Nishi, Tokyo, JP;
Toru Kiuchi, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An exposure method for irradiating a mask with an illumination light through an illumination optical system and exposing photosensitive substrate to the illumination light through a projection optical system including the steps of supplying gas having less absorption of the illumination light to a light path of the illumination light, at least a portion of the illumination optical system and the projection optical system; and changing an exposing condition for the photosensitive substrate in accordance with a variation in transmittance or in reflectance of at least one of the illumination optical system and the projection optical system, resulting from irradiation of the illumination light and attenuation of the illumination light in the light path.