Patent ID: 6961132
Filing Date: 2005-11-01
Classification: G01B,G01J,G03F

Abstract:
1. An exposure apparatus for exposing a substrate with a pattern of an original, said apparatus comprising: a projection optical system for projecting the pattern of the original onto the substrate with light from a light source; an optical path difference applying optical system for dividing light from the light source into two light beams and for re-combining the two light beams; an optical unit for directing light from said optical path difference applying optical system to a pinhole; and an interferometer for measuring an optical characteristic of said projection optical system by use of the light from said optical path difference applying optical system which passes the pinhole and said projection optical system, wherein the pinhole is disposed at a focal point position of said optical unit, and wherein the pinhole has a diameter which is smaller than a diameter of an Airy disc.