US Patent 7619748 Exposure apparatus mounted with measuring apparatus

An exposure apparatus for exposing a pattern of a mask onto an object using light from a light source, includes a projection optical system for projecting the pattern onto the object, and a measuring apparatus for measuring, as an interference fringe, optical performance of the projection optical system using the light, wherein the measuring apparatus is a point diffraction interferometer that has a pinhole to form an ideal spherical wave, a line diffraction interferometer that has a slit to form an ideal cylindrical wave or an ideal elliptical wave, or a shearing interferometer that utilizes a shearing interferometry.