摘要：

An alignment apparatus for aligning one of the substrates with the other by means of first and second reference marks comprises scanning means including a light beam generating means for reciprocally scanning first and second areas respectively by a light beam, discrimination means for generating a discrimination signal indicative of the scanning direction by the scanning means in synchronism with the scanning, first photoelectric means for generating a first signal when the first photoelectric means receives the light beam transmitted through a first area and separated by the first reference mark, second photoelectric means for generating a second signal when the second photoelectric means receives the light beam transmitted through the second area and separated by the second reference mark, operation means for determining the direction and amount of the relative deviation between the first and second reference marks from the first and second signals and from the discrimination signal, and means for moving one of the substrates relative to the other in response to the operation means. The alignment apparatus is simple in structure and can detect alignment marks with higher accuracy. The alignment apparatus enables the alignment of a wafer with a reticle or mask at higher speed and with higher preciseness.

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