PROJECTION LENS SYSTEM OF A MICROLITHOGRAPHIC PROJECTION EXPOSURE INSTALLATION

摘要

A microlithographic projection exposure installation comprises a projection lens system (20), which projects an object (24) onto a focal plane (28) and which has a lens (L3) with a curved surface (S). A liquid or solid medium (34) is located in the projection lens system (20) and directly abuts against the curved surface (S) over an area that can be used for the projection of the object (24). The projection exposure installation also comprises an adjustable manipulator (M) for reducing a curvature of field that is caused by a heating of the medium (34) during the projection operation.