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:
Aug. 22, 1989
Filed:
Jul. 06, 1988
Seiro Murakami, Tokyo, JP;
Akikazu Tanimoto, Yokohama, JP;
Susumu Makinouchi, Yokohama, JP;
Hidemi Kawai, Kawasaki, JP;
Masaichi Murakami, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An apparatus for detecting a position of a reference pattern or mark formed in a substrate to be aligned with a photomask pattern performs the following functions: scanning a reference pattern having at least two edges and generating a time-serial pattern signal corresponding to the scanned pattern; extracting all scanning positions at which a waveform of the pattern signal has a shape corresponding to an edge of the pattern within a predetermined scanning range including the pattern; selecting one pair from all possible pairs of a plurality of extracted scanning positions in accordance with a degree to which a pattern signal between the two scanning positions defined by each pair satisfies predetermined waveform conditions; and determining as a pattern position a predetermined position at which the interval between the two scanning positions of the selected pair is divided into two intervals by a predetermined ratio.