Patent ID: 6733165
Filing Date: 2004-05-11
Classification: G03F,Y10S

Abstract:
An optical integrator for an illumination device for a microlithographic projection exposure system, the optical integrator comprising:a rod made of a material transparent to the light of a light source; the rod comprising an entrance surface optically facing towards the light source and an opposing exit surface; the rod further comprising an essentially rectangular cross section having a width and a height perpendicular to the width, an aspect ratio between the width and the height of the cross section deviating from unity; and compensation means for compensating direction-dependent total reflection losses of the rod; wherein the compensation means includes at least one transparent compensation section having a second, rectangular cross section, the cross section having a second width and a second height perpendicular to the second width, wherein the second width is larger than the second height, the compensation section being formed in such a way that total reflection losses in the compensation section are greater in the direction of the width of the rod than in the direction of the height of the rod.