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:
Oct. 15, 1996
Filed:
Feb. 07, 1995
Kei Nara, Yokohama, JP;
Nobutaka Fujimori, Fujisawa, JP;
Nikon Corporation, Tokyo, JP;
Abstract
In an alignment method an apparatus for scanning an alignment mark formed on a substrate with a beam of light, and detecting the position of the alignment mark on the basis of a signal conforming to reflected light obtained from the alignment mark, a dummy mark of the same shape as the alignment mark is formed near the alignment mark formed on the substrate, the dummy mark and the alignment mark are continuously scanned by the beam of light, and during the time from after the beam of light has scanned the dummy mark until the scanning of the alignment mark is started, the intensity (signal level) of a first signal obtained in conformity with reflected light reflected by the dummy mark is found to thereby calculate the amplification factor of the signal, and during the scanning of the alignment mark, a second signal obtained in conformity with reflected Light reflected from the alignment mark is amplified with this amplification factor, and the position of the alignment mark is detected on the basis of the amplified second signal.