Patent ID: 9678437
Date: 2017-06-13
CPC Classifications: G03B,G03F

Claim:
1. An illumination optical apparatus which illuminates a pattern on a mask with illumination light, the illumination optical apparatus comprising: an optical integrator arranged in an optical path of the illumination light; a polarization member arranged in the optical path of the illumination light on an incidence side of the optical integrator, which changes a polarization state of the illumination light; and a movable member arranged in the optical path between the polarization member and the optical integrator so as to change a light amount distribution of the illumination light on a pupil plane of the illumination optical apparatus, wherein the polarization member changes the polarization state of the illumination light distributed away from an optical axis of the illumination optical apparatus on the pupil plane so that a polarization direction of the illumination light at a distribution area on the pupil plane is substantially perpendicular to a radial direction extending from the optical axis to the distribution area.