Flow physics and modeling in extreme ultraviolet sources

The development of high-power extreme ultraviolet (EUV) light sources based on the laser-produced plasma (LPP) principle is crucial for advanced lithography, enabling the continued scaling of semiconductor devices. However, the underlying processes-involving laser-droplet interaction, plasma evolution, and debris transport-are governed by complex, multiscale, and multiphysics phenomena that pose significant challenges for both simulations and experiments. This review comprehensively surveys recent advances in the flow physics and modeling of LPP-EUV sources, focusing on three key areas: (i) numerical modeling and simulation of laser-tin droplet interaction, including laser absorption, radiation transport, equation of states, etc.; (ii) progress in understanding droplet dynamics under femtosecond to nanosecond laser pulses; and (iii) the flow physics of debris transport and mitigation strategies such as buffer gas jets and magnetic fields. By integrating insights from simulations, experiments, and theoretical analyses, this review aims to bridge the gap between fundamental flow physics and applied EUV source engineering, providing a valuable reference for researchers working toward more efficient and debris-resistant EUV light sources.