Patent ID: 6023320
Filing Date: 2000-02-08
Classification: G03F

Abstract:
A scanning exposure apparatus, wherein a pattern of a surface of a first object placed on a first stage is illuminated with exposure light from a slit aperture of illumination means, and wherein the pattern of the first object is projected through a projection optical system onto a surface of a second object placed on a second stage while relatively and scanningly moving said first and second stages in a widthwise direction of the slit aperture, in a timed relation and at a speed ratio corresponding to a projection magnification of said projection optical system, said apparatus comprising:a reference plate provided in a portion of one of said first and second stages and having a predetermined mark;a reflection surface plate provided in a portion of the other of said first and second stages, anda surface position detecting system for projecting the mark of said reference plate onto said reflection surface plate through said projection optical system and, while moving one of said first and second stages in a direction of an optical axis, for detecting the position of the surface of the second object in the direction of the optical axis on the basis of an image reflected by said reflection surface plate.