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. 09, 1979
Filed:
May. 25, 1976
Hitachi, Ltd., , JP;
Abstract
An alignment apparatus, in which a mask is overlaid on a wafer and a relative displacement between the wafer and a target pattern formed on the mask is detected to effect alignment thereof, comprises a slit frame adapted to reciprocate in a direction substantially parallel to the top surface of the mask and having a slit formed therein, an illumination optical system for illuminating the target pattern, an image formation optical system for forming the image of the target pattern onto the slit of the slit frame, a light sensing element mounted on the slit frame for detecting the target pattern image formed by the image formation optical system through the slit to convert the image into an electric signal, and a displacement detector for detecting the amount of movement of the reciprocation of the slit frame to convert the amount of movement into a position signal which the light sensing element scans, whereby the output signals from the displacement detector and the light sensing element are used to detect the relative position between the mask and the target pattern on the wafer and the mask is moved relative to the wafer such that the relative displacement amount becomes zero.