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. 21, 1997
Filed:
Dec. 15, 1995
Abstract
A narrow-band excimer laser employing a diffraction grating as a wavelength selective element, which is particularly suited for a light source of a reduction projection aligner. The grating used in the narrow-band excimer laser of the invention is so disposed that the ruling direction of the grating is nearly perpendicular to the direction of laser discharge. When a beam expander is used to expand laser beam falling on the beam expander is so disposed that the direction of beam expansion is nearly perpendicular to that of discharge of the laser. Further, when an aperture is to be used in the laser cavity, the aperture is placed so that the longitudinal direction may be parallel to the direction of laser discharge. Moreover, the front mirror of the laser cavity is a cylindrical one, whose mechanical axis is in parallel with the direction of laser discharge. This makes it possible to provide a narrow-band excimer laser having very high efficiency and excellent durability.