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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.

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First Claim