Patent ID: 6778255
Filing Date: 2004-08-17
Classification: G03B,G03F

Abstract:
An exposure apparatus for illuminating a reticle with exposing light from an exposing light source via an illuminating optical system and projecting a pattern, which has been formed on the reticle, onto a substrate via a projection optical system, said apparatus comprising:a vessel within which one of the illumination optical system and the projection optical system is placed; gas supplying means for supplying a desired gas to said vessel; vacuum exhaust means for vacuum evacuating said vessel in order to establish negative pressure in the interior thereof from atmospheric pressure; and control means for controlling a differential pressure between an internal pressure of said vessel and the atmospheric pressure so as not to exceed a differential pressure constant, wherein said gas supplying means supplies the desired gas to said vessel after a pressure in said vessel is reached at a predetermined vacuum pressure by said vacuum exhaust means, and said vacuum exhaust means is atmosphere-released if a concentration of gas in said vessel attains a predetermined concentration.