Patent ID: 7812927
Filing Date: 2010-10-12
Classification: G03F

Abstract:
1. A scanning exposure apparatus for performing exposure of a substrate to light via an original, while the substrate and the original are scanned, said apparatus comprising: a projection optical system configured to project light from the original onto the substrate; a stage configured to hold the substrate and to move in a scanning direction perpendicular to an optical axis of said projection optical system; and a focus detector configured to detect a position of a surface region of the substrate in a direction of the optical axis, said apparatus being configured (i) to detect, using said focus detector, a position of the surface region with respect to each of a plurality of shot regions of the substrate to obtain a plane that approximates a surface of the substrate, (ii) to detect, using said focus detector, with the surface of the substrate aligned with the plane, the position of the surface region with respect to each of a plurality of measurement points in each of a plurality of shot regions of the substrate, (iii) to average the detected positions obtained in (ii) over the plurality of shot regions with respect to each of the plurality of measurement points, (iv) to obtain a function which represents a surface that approximates the averaged positions respectively obtained with respect to the plurality of measurement points, (v) to calculate a difference between each of the averaged positions and a value of the obtained function with respect to each of the plurality of measurement points, (vi) to offset a position detected by said focus detector with respect to each of the plurality of measurement points in a shot region of the substrate with a corresponding one of the calculated differences during the exposure, and (vii) to control a position of said stage based on each of the offset positions during the exposure.