REFERENCE POSITION MEASURING INSTRUMENT AND METHOD, AND DRAWING DEVICE

摘要

PROBLEM TO BE SOLVED: To correct a position detection error of a reference mark due to variance in a vertical direction, without reducing throughput.

SOLUTION: A camera 25 of an alignment unit 24 is provided with a Z-direction sensor 26 which measures a variation Δ from an in-focus position of a substrate upper face. A distortion correction part 58 for correcting a photographic image of the reference mark includes: a correction data storage part 59 wherein distortion correction data corresponding to the variation Δ from the in-focus position is stored with respect to a plurality of variations Z-direction sensor 26; and an image correction processing part 61 which uses distortion correction data determined by the correction data determination part 60 to correct distortion of the photographic image. Thus the position detection error of the reference mark due to variance in the vertical direction can be corrected without vertically moving a substrate.

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