Patent ID: 7209215
Filing Date: 2007-04-24
Classification: G03B,G03F

Abstract:
1. An exposure apparatus for exposing a pattern of a reticle onto a plate while synchronously scanning the reticle and the plate, the exposure apparatus comprising: a projection optical system for projecting the pattern of the reticle onto the plate; a measuring part for measuring a position of a surface of a target to be measured in an optical axis direction of the projection optical system; and a controller for controlling the position of the surface of the target in the optical axis direction based on a measurement result by the measuring part, wherein the measuring part measures the position of the surface of the target by projecting plural mark images onto the surface of the target and detecting the plural mark images on the surface of the target, and projects at least three mark images among the plural mark images onto a same measurement point on the target, wherein the controller uses, as a measurement value of the same measurement point, an average value of plural measurement results obtained by detecting the at least three mark images at the same measurement point, wherein the at least three mark images are arranged at regular intervals, and only a central mark image among the at least three mark images is formed on the surface of the target, and wherein the target is the reticle or the plate.