A liquid immersion exposure apparatus includes a projection optical system (PL) which projects an image of a pattern onto a substrate (W) and a unit (5) which supplies a liquid (7) between an optical element (4) at the end of the projection optical system (PL) and the substrate (W). A corrosion-resistant...http://www.google.com/patents/US20050225738?utm_source=gb-gplus-sharePatent US20050225738 - Optical element and projection exposure apparatus based on use of the optical element
