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:
Nov. 19, 1985
Filed:
Oct. 22, 1982
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An alignment apparatus for aligning a mask having a first mark comprising first mark elements and a wafer having a second mark comprising second mark elements different in width from the first mark elements, comprises a moving mechanism for moving the wafer, a sensor for detecting the first and second marks and putting out a detection signal stream, a signal processing circuit for receiving the detection signal stream, discriminating between the first mark elements and the second mark elements in accordance with their respective pulse widths and creating a discrimination signal and creating a spacing signal regarding a plurality of spacings between the first mark elements and the second mark elements, and a drive circuit for driving the moving mechanism in response to the discrimination signal and the spacing signal. When the first and second mark elements overlap each other or come close to each other and the signals of the two elements cannot be separated, the wafer is moved by a predetermined amount, whereafter detection of the marks is again effected.