PROJECTION OPTICAL SYSTEM, EXPOSURE DEVICE AND EXPOSURE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a projection optical system of reflection/refraction type capable of securing an adequately large actuation distance between a mask or a photosensitive substrate and a major optical system while securing a sufficiently large numerical aperture of image side. SOLUTION: The projection optical system is provided with: a major optical system MO having a reflective principal mirror CM and a first lens group G1 arranged in the go-and-return optical path; a first back surface reflective prism P1 which reflects light from a first surface M toward the major optical system; a second back surface reflective prism P2 which reflects light from the major optical system toward a second surface P; a second lens group G2 which is arranged in an optical path between the first surface and the first back surface reflective prism; and a third lens group G3 which is arranged in an optical path between the second back surface reflective prism and a second surface. COPYRIGHT: (C)2005,JPO&NCIPI