Patent ID: 6236449
Filing Date: 2001-05-22
Classification: G02B,G03F

Abstract:
An exposure apparatus for patterning a photosensitive substrate with a pattern formed on a mask, comprising:an illumination optical system for illuminating the mask; anda projection optical system arranged in an optical path between the mask and the photosensitive substrate, so as to project an image of the pattern formed on the mask onto the photosensitive substrate;wherein said illumination optical system comprises:a light source for providing a light beam having a cross-sectional shape;a light guide optical system disposed in the optical path between said light source and the mask, so as to guide the light beam to a convergence point;an internal reflection-type integrator disposed in the optical path between said light guide optical system and the mask so as to form a plurality of secondary light sources, said internal reflection-type integrator having a rectangular cross-sectional shape with a first side of length dx alone a first direction perpendicular to an optical axis and a second side dy along a second direction perpendicular to the first direction and perpendicular to the optical axis, and an incident surface spaced from the convergence point along the optical axis by spacing L; andan imaging optical system disposed in the optical path between said internal reflection-type integrator and the mask so as to direct the light beam to the mask;wherein the following conditions are satisfied:0.1.ltoreq.L.ltoreq.dx/(2.times.tan .alpha.x)0.1.ltoreq.L.ltoreq.dy/(2.times.tan .alpha.y),wherein .alpha.x is an angle of said light beam incident to said incident surface, as measured in a first plane parallel to the first direction that includes the optical axis, and .alpha.y is an angle of the light beam incident to said incident surface, as measured in a second plane orthogonal to said first plane that includes the optical axis.