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, 2003
Filed:
Jun. 21, 2000
Ushio Denki Kabushiki Kaisya, Tokyo, JP;
Abstract
The present invention relates to a wavelength monitoring apparatus capable of measuring both standard light and laser light for semiconductor exposure simultaneously and highly accurately, without a time lag. Entrance-side optical systems and allow light from a laser for semiconductor exposure and reference light from a He—Ne laser to be incident on different areas of a single etalon in the form of diverging light, converging light or diffused light in such a manner that the respective center axes thereof are displaced relative to each other. Two focusing optical systems and are provided in approximately coaxial relation to the respective center axes of the laser light and reference light passing through the etalon A one-dimensional array optical sensor is placed in a plane P coincident with the back focal planes of the focusing optical systems and to receive interference fringes produced by the laser light and the reference light. The positions of the interference fringes on the one-dimensional array optical sensor are detected to calculate the wavelength of the laser light for semiconductor exposure.