INTERFEROMETER, EXPOSURE DEVICE AND EXPOSURE METHOD

摘要

PROBLEM TO BE SOLVED: To provide an interferometer capable of measuring in high accuracy even when a moving mirror is slightly tilted. SOLUTION: This interferometer 90 for measuring the displacement of the moving mirror in accordance with an interference of a reference beam going to and from a fixed mirror 89 on an optical path and a measuring beam going to and from the moving mirror 88 on the optical path is provided with a wave front adjusting means 5 adjusting a wave front of the reference bean (or the measuring beam) to restrain the occurrence of a measurement error attributable to a tilt of the moving mirror. The wave front adjusting means is provided in the optical path between a beam splitter 2 splitting a beam from a beam source 1 into the reference beam going to the fixed mirror and the measuring beam going to the moving mirror and the fixed mirror (or the moving mirror). COPYRIGHT: (C)2003,JPO