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. 11, 1988
Filed:
Oct. 14, 1986
Akira Inagaki, Yokohama, JP;
Yukio Kembo, Yokohama, JP;
Ryuichi Funatsu, Yokohama, JP;
Asahiro Kuni, Tokyo, JP;
Keiichi Okamoto, Yokohama, JP;
Yoshihiro Komeyama, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method and apparatus for alignment for use in X-ray exposure or the like wherein a mask is provided having a formation of an alignment pattern made up of at least one linear segment formed in a peripheral section of the mask and a wafer is provided having a formation of an alignment pattern formed in a same direction as the alignment pattern of the mask and made up of linear segments. An illuminating arrangement illuminates a light to the mask alignment pattern along a direction inclined to the alignment direction and the mask alignment pattern and the wafer alignment pattern are imaged and transformed into a video signal. An A/D converts the video signal into a digital signal and stores the digital signal in a memory. The digital video signal is read out from the memory and averaged in a mask alignment pattern by removing a shadow portion caused by the mask alignment pattern and additionally averaged in a wafer alignment pattern area with an averaged wafer alignment pattern signal and an averaged wafer alignment pattern signal being provided. Relative displacement between the mask and the wafer is detected from the averaged mask alignment pattern signal and the averaged wafer alignment pattern signal and the mask and wafer are aligned by moving at least one of the mask and wafer so that displacement between the mask and the wafer does not exist.