High-power excimer laser homogenization using dual-microlens arrays

The high-power excimer laser is widely used in advanced lithography. To meet the high requirements for beam uniformity in lithography illumination systems, we researched excimer laser homogenization using microlens arrays. This paper proposes a tunable excimer laser model that more accurately reflects the conditions of practical light sources based on the far-field propagation characteristics of multi-Gaussian Schell-model partially coherent light. Furthermore, a high-power excimer laser homogenizer is designed by combining matrix optics and scalar diffraction theory to achieve a square beam with a low non-uniformity of 1.28%. Finally, the effects of pointing stability, positional stability, and spot size variation of the excimer laser on uniformity are analyzed, and the accuracy and reliability of the proposed excimer laser model are verified experimentally.