SYSTEMS AND METHODS FOR INSITU LENS CLEANING IN IMMERSION LITHOGRAPHY

摘要

PURPOSE: A system and a method for cleaning a lens in-situ in immersion lithography is provided to prevent the damages to final lens elements and to efficiently performing an in-situ cleaning process of final lens elements without removing the leans and repositioning the lens. CONSTITUTION: An apparatus for immersion lithography comprises: an energy source(110); a projection optical system(130); a stage(160) which a substrate(150) is arranged in and moves the substrate; a showerhead including an immersion liquid feed device and an immersion liquid discharge device; and a cleaning device which cleans a part of the projection optical system contacting immersed liquid(140) through cleaning gas. The cleaning device includes a UV source.