Method and apparatus for detecting position of a mark

U.S. Patent Number: 5392361

Abstract: A mark position detecting method and apparatus, suitably usable in a semiconductor device manufacturing exposure apparatus, called a stepper, prints images of a pattern of a reticle upon different shot areas on a semiconductor wafer, and aligns the reticle and the wafer. In this method, fuzzy reasoning is made by using, for example, a membership function which empirically represents the relationship between a mark signal and an alignment result. By using a conclusion of the fuzzy reasoning, the position of the mark is detected. Thus, the alignment accuracy can be improved significantly.

Inventors: Imaizumi; Masaaki (Tokyo, JP), Nishimori; Eiji (Tokyo, JP), Ichida; Yasuteru (Machida, JP), Ayata; Naoki (Machida, JP)

Assignee: Canon Kabushiki Kaisha (Tokyo, JP)

Application Number: 08/137,804

Issued: 1995-02-21

Expired: 2007-02-21

Classes: 382/260 ; 382/295; 706/52; 706/900

Field of search: 382/8,14,15,48 364/807,274.6 395/10,21,61,62

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