Electrochemically Synthesized Tin/Lithium Alloy to Convert Laser Light to Extreme Ultraviolet Light

This paper describes lithium-tin alloys as a novel target material to enhance the efficiency of 13.5 nm extreme ultraviolet (EUV) light from generated laser-produced plasmas. Both lithium and tin exhibit EUV emission with the same peak at 13.5 nm. We show that lithium-tin (LiSn) alloys exhibit emission also at 13.5 nm and a mixture of tin and lithium emission by illuminating Nd:YAG laser (1 ns, 2.5 × 10¹⁰, 7.1 × 10¹⁰ W/cm²). The emission spectra and emission angular distribution by using phosphor imaging plates were analyzed to obtain the conversion efficiency from laser light to 13.5 nm light. The Li-Sn alloys were slightly higher than planar tin and between tin and lithium. It would be due to the suppression of self-absorption of 13.5 nm light by the tin plasma.