Beam transforming optical system, illumination optical apparatus, exposure apparatus, and exposure method with optical member with optical rotatory power having different thickness to rotate linear polarization direction

Abstract

An illumination optical apparatus illuminates a pattern on a mask with illumination light. The illumination optical apparatus includes an optical integrator arranged in an optical path of the illumination light, and a polarization member made of optical material with optical rotatory power, which is arranged in the optical path on an incidence side of the optical integrator, and which changes a polarization state of the illumination light. The illumination light from the polarization member is irradiated onto the pattern through a pupil plane of the illumination optical apparatus.

1 . An illumination optical apparatus which illuminates an object with illumination light, the illumination optical apparatus comprising:
 an optically active member which includes a first element and a second element which are made from an optically active material and which rotate a polarization direction of the illumination light by the action of optical activity of the optically active material, the first and second elements being arranged in an optical path of the illumination light such that an optic axis of the optically active material is substantially parallel to an optical axis of the illumination optical apparatus;   an optical integrator arranged in the optical path between the optically active member and an illumination pupil of the illumination optical apparatus;   wherein the first and second elements are located at different positions from each other with respect to an direction orthogonal to the optical axis of the illumination optical apparatus so that a first surface of the first element and a second surface of the second element face each other, the first and second surfaces having different lengths from each other with respect to an direction of the optical axis.