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:
Jan. 04, 2011
Filed:
Feb. 16, 2007
Noriyuki Hirayanagi, Tokyo, JP;
Noriyuki Hirayanagi, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An exposure apparatus transfers a pattern from a mask onto a sensitive substrate. A film protects the mask, and a film frame, between the mask and the film, holds the film spaced away from a surface of the mask. The film has a first transmittance for radiation of a necessary wavelength and has a second transmittance for radiation of an unnecessary wavelength; the first transmittance is higher than the second transmittance. The film might reflect or absorb the unnecessary wavelength. The necessary wavelength may be an exposure wavelength and may also be in the range of extreme ultra violet radiation. An atmosphere around the mask transitions from an air atmosphere to a reduced-pressure atmosphere, or from a reduced-pressure atmosphere to an air atmosphere, at a speed that allows a difference between a pressure applied to one surface of the film and a pressure applied to the other surface of the film to be held at a predetermined value or smaller.