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:
Mar. 07, 1995
Filed:
Dec. 02, 1991
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A method of detecting a positional deviation between a mask and a wafer, wherein a radiation beam having a predetermined intensity distribution is projected to an alignment pattern of the mask whereby a signal beam is produced, and wherein the positional deviation of the mask and the wafer is determined on the basis of the signal beam. The improvements reside in detecting a deviation of the position of incidence of the radiation beam upon the mask from a predetermined position, on the basis of the signal beam; relatively positioning the radiation beam and the mask so as to substantially correct the detected deviation; and determining the positional deviation of the mask and the wafer by using the relatively positioned radiation beam.