[10a-S301-1~10] 8.1 Plasma production and diagnostics

[10a-S301-1] Time and spatial resolved laser Thomson scattering measurement in hydrogen plasmas induced by laser produced Sn plasma radiation

〇Kouichiro Kouge¹, Kentaro Tomita^2,3, Junya Hotta², Yiming Pan², Hiroaki Tomuro¹, Masayuki Morita¹, Tatsuya Yanagida¹, Kiichiro Uchino², Naoji Yamamoto² (1.Gigaphoton Inc., 2.Kyushu Univ., 3.Hokkaido Univ.)

Keywords:EUV, Thomson scattering

Hydrogen is used as a buffer gas inside the light source for extreme ultraviolet (EUV) lithography, and the radiation of laser-produced Sn plasma, which is used for EUV generation, ionizes the hydrogen to generate hydrogen plasma (Sn-LPP radiation induced hydrogen plasma). In the operating EUV light sources, the hydrogen radicals and ions in this plasma are assumed to suppress the contamination of the EUV collecting mirror. Therefore, it is important to understand the parameters of this plasma, such as electron density (n_e) and electron temperature (T_e), to understand the environment to which the EUV collector is exposed. In this study, we measured the spatial and temporal distributions of n_e and T_e in Sn-LPP radiation-induced hydrogen plasma by laser Thomson scattering method. The results are reported in this presentation.