Illumination optical apparatus containing an optical integrator and projection exposure apparatus using the same

摘要

An illumination optical apparatus has an optical integrator and a condenser optical system. The optical integrator has first and second stages in which a plurality of lens elements each having a rectangular lens surface with long and short sides are arranged while the short sides are set adjacent to each other. The first and second stages are arranged adjacent to each other. A position where the short sides are adjacent to each other in the first stage is different from that in the second stage along a longitudinal direction. Therefore, in the illumination optical apparatus, a resolution difference between a pattern along the vertical direction and that in the horizontal direction caused by a rectangular illuminated area with long and short sides or an arcuated illuminated area can be prevented, so that resolution with a uniform line width can be achieved.