Post-discharge study of laser-triggered vacuum discharge for highly repetitive powerful EUV source

摘要

Extreme ultraviolet (EUV) source remains a key issue for industrial application of EUV lithography. Currently, laser-triggered discharge (LTD) tin plasma is the most promising discharge produced plasma EUV source. High frequency discharge of up to tens of kHz is required to achieve sufficient average radiation power. However, the choice of discharge frequency is restricted by the recovery time of the tin fuel plasma. Although much experimental and theoretical work has been performed to investigate discharge plasma dynamics and its corresponding EUV radiation process during main discharge, study regarding post-discharge stage after main discharge is scant.