LIGHT INTEGRATOR FOR ILLUMINATION DEVICE

摘要

PROBLEM TO BE SOLVED: To improve illumination uniformity of an illumination device, especially in angle-dependent light intensity nonuniformity. SOLUTION: A light integrator used for the illumination device of a microlithographic illumination exposure system is equipped with a rod (27), which is formed of ultraviolet-ray transmitting material and rectangular is cross section. For instance, a rod structure (29), composed of seven small rods (30) of the same material, is disposed in front of an inlet surface (28) of the rod (27). The aspect ratio of the width to the height of the small rod (30) is the inverse of that of the rod (27). The rod structure (29) serves as a compensating means for compensating for direction-dependent total reflection loss in the rod (27).