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:
Apr. 07, 1987
Filed:
Nov. 09, 1983
Naoki Ayata, Machida, JP;
Yasuyoshi Yamada, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A mask aligner includes a photo-mask having a plurality of first marks used to align the photo-mask with a wafer and a plurality of second marks used to align the photo-mask with the mask aligner, the number of the second marks being equal to that of the first marks; a wafer having a plurality of third marks associated with the first marks; a mark providing section having a plurality of fourth marks associated with the second marks; and a detector for detecting an error in alignment between the first and third marks and also an error in alignment between the second and fourth marks, the detector including a plurality of sensors for sensing various marks in different positions, a basic form produced when the first and third marks are placed one above another being substantially the same as that produced when the second and fourth marks are placed one above another.