Laser-Imaging Diagnostics of Debris Behavior from Laser-Produced Tin Plasma for EUV Light Sources

摘要

In the development of extreme ultraviolet (EUV) light source for EUV lithography systems by laser-produced plasma (LPP), reduction of debris emitted from the plasma such as ions, droplets and neutral atoms is one of the most important factors. In our study, we developed a two-dimensional (2D) laser-induced fluorescence (LIF) imaging system for neutral atoms from the plasma and investigated neutral debris behaviors in order to obtain the guideline for the optimization of debris shields. Dependence of atomic emission on a thickness of LPP Sn target film was observed and the distributions of emitted neutral atoms in H_2 gas were measured by 2D LIF system.