METHOD FOR MEASURING POSITION OF PATTERN ON FRONT AND BACK FACE OF SUBSTRATE AND MEASUREMENT APPARATUS USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for accurately measuring a displacement between markers on front and back faces even if a normal of a photomask substrate is shifted relative to a rotating shaft of a measuring stage.

SOLUTION: The method for measuring positions of patterns on the front and back faces of the substrate comprises: a first displacement measuring step for obtaining a first displacement between the patterns on the front and back faces of the photomask substrate 1 by two times of measurements before and after the measuring stage 10 is rotated by 180°in a first state that the photomask substrate 1 is placed on the rotatable measuring stage 10; a second displacement measuring step for obtaining a second displacement between the patterns on the front and back faces of the photomask substrate 1 by two times of measurements before and after the measuring stage 10 is rotated by 180°in a second state that the photomask substrate 1 is rotated from the first state at an angle of 90°or 180°; and a true displacement calculating step for calculating a true displacement from the first and second displacements.

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