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. 16, 2003
Filed:
Nov. 14, 2000
Akifumi Tada, Gotenba, JP;
Ushio Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An excimer laser apparatus using a bandwidth-narrowing optical system including a beam diameter-enlarging optical system and a Littrow mounting reflection type diffraction grating is made suitable for use as a laser light source for semiconductor lithography or the like by surmounting the limit to bandwidth narrowing due to wavefront distortion induced by the reflection type diffraction grating. In an excimer laser apparatus having a bandwidth-narrowing optical system including a Littrow mounting reflection type diffraction grating and a combination of a beam diameter-enlarging optical system and a slit placed on the entrance side of the reflection type diffraction grating, diffracted wavefront distortion (a measured value for He—Ne laser light) within the laser irradiation area of the reflection type diffraction grating in Littrow mounting is not more than &lgr;/10, where &lgr; is a measuring wavelength.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile