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:
Feb. 19, 2002
Filed:
Apr. 05, 1999
Naoto Sano, Utsunomiya, JP;
Canon Kabushiki Kaishia, Tokyo, JP;
Abstract
A semiconductor device manufacturing method includes the steps of providing a projection exposure apparatus, exposing a wafer by using the projection exposure apparatus, the exposing step including projecting a circuit pattern onto the wafer through the projection optical system using light from a first laser, and developing the exposed wafer. Before the providing step, an optical performance of the projection optical system is measured by producing an interference fringe, bearing information related to aberration of the projection optical system, by use of a harmonic of a second laser having a coherency higher than that of the first laser, and then by analyzing the interference fringe. A wavelength of the light from the first laser is registered with that of the harmonic of the second laser.