Exposure apparatus and device manufacturing method using a common path interferometer to form an interference pattern and a processor to calculate optical characteristics of projection optics using the interference pattern

Abstract

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