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, 1990
Filed:
Jan. 25, 1989
Yuichi Yamada, Kawasaki, JP;
Naoki Ayata, Machida, JP;
Hiroki Suzukawa, Yokohama, JP;
Hideki Nogawa, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Mark detecting method and apparatus usable, for example, in a semiconductor exposure apparatus such as a stepper for printing a pattern of a reticle upon a semiconductor wafer, for detecting, by using an image sensor, an alignment mark provided on a reticle or wafer for alignment of the same. Plural search marks are provided two-dimensionally around the alignment mark, each search mark having a first pattern and one or more second patterns indicative of the position of the alignment mark. When at least one first pattern of the search mark is caught by an image pickup device, the reticle is displaced in accordance with the positional information as indicated by the second pattern of the search mark. This brings the alignment mark within the image pickup region of the image sensor. The alignment mark is subsequenlty used to accurately align the reticle with a predetermined position. Thus, the time required for completing the reticle alignment can be reduced remarkably.