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:
Jun. 08, 2010
Filed:
Jun. 23, 2006
Yasuhiro Kishikawa, Utsunomiya, JP;
Yasuhiro Kishikawa, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An exposure apparatus includes an illumination optical system for illuminating a reticle with exposure light, a projection optical system for projecting a pattern of the reticle onto a plate via a liquid supplied to a space between the projection optical system and the plate, a supply pipe for supplying the liquid to the space, a recovery pipe for recovering the liquid from the space, and a measuring unit for measuring a refractive index of the liquid. The measuring unit includes (i) a light source for generating a measurement light having the same wavelength as that of the exposure light, (ii) a liquid reservoir for storing the liquid, the liquid reservoir being disposed apart from the space via the supply pipe or the recovery pipe, and having a transmitting surface for transmitting the measurement light and a reflecting surface for reflecting the measurement light transmitted by the transmitting surface and the liquid in the reservoir, and (iii) a detector for detecting the measurement light reflected on the reflecting surface and transmitted by the liquid in the liquid reservoir and the transmitting surface.