Patent ID: 7675629

Claim:
An exposure apparatus including an illumination system which illuminates an original, and projection optics which project a pattern of the original illuminated by said illumination system onto a substrate, said apparatus comprising: an interferometer which forms an interference pattern including aberration information on said projection optics using a polarized light beam emitted from said illumination system, wherein said interferometer is a common path interferometer in which two light beams forming an interference pattern pass along a path in said projection optics; and a processor which calculates optical characteristics of said projection optics on the basis of the interference pattern formed by said interferometer, wherein said illumination system includes a polarization controller which sequentially generates at least three different polarized light beams with respective polarization states different from each other, and wherein said processor separates first aberration and second aberration from wavefront aberration represented by the interference patterns sequentially formed by said interferometer using said at least three different polarized light beams, by calculating data of the interference patterns, the first aberration being aberration which does not change dependent on a polarization state of a polarized light beam entering said projection optics, and the second aberration being aberration which changes dependent on the polarization state of the polarized light beam entering said projection optics.