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. 09, 2008
Filed:
May. 31, 2005
Illumination optical system, exposure apparatus, and exposure method with polarized switching device
Osamu Tanitsu, Saitama, JP;
Hirohisa Tanaka, Saitama, JP;
Kenichi Muramatsu, Kanagawa, JP;
Norio Komine, Kanagawa, JP;
Hisashi Nishinaga, Saitama, JP;
Tomoyuki Matsuyama, Kurihashi-machi, JP;
Takehito Kudo, Saitama, JP;
Osamu Tanitsu, Saitama, JP;
Hirohisa Tanaka, Saitama, JP;
Kenichi Muramatsu, Kanagawa, JP;
Norio Komine, Kanagawa, JP;
Hisashi Nishinaga, Saitama, JP;
Tomoyuki Matsuyama, Kurihashi-machi, JP;
Takehito Kudo, Saitama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An illumination optical system for, when installed in an exposure system, realizing a suitable illumination condition by varying the polarized state of the illumination light according to the pattern characteristics of the mask while suppressing the loss of the intensity of the light. The illumination optical system has a light source unit for supplying a linearly polarized light for illuminating surfaces to be illuminated therewith, and a polarized state changing device for changing the polarized state of the illuminating light from a predetermined polarized state to a nonpolarized state and vice versa. The polarized state changing device is arranged in the optical path between the light source unit and the surfaces to be illuminated. The polarized state changing device can be removed from the illumination optical path and has a depolarizer for selectively depolarizing the incident linearly polarized light.