›› 2014, Vol. 23 ›› Issue (7): 75202-075202.doi: 10.1088/1674-1056/23/7/075202
• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇 下一篇
窦银萍, 孙长凯, 刘超智, 高健, 郝作强, 林景全
Dou Yin-Ping (窦银萍), Sun Chang-Kai (孙长凯), Liu Chao-Zhi (刘超智), Gao Jian (高健), Hao Zuo-Qiang (郝作强), Lin Jing-Quan (林景全)
摘要: For the next-generation beyond extreme ultraviolet lithography (EUVL) sources, gadolinium (Gd) plasma with emission wavelength at 6.7 nm seems to be the leading candidate. Similar to the Sn target 13.5 nm light source, ion debris mitigation is one of the most important tasks in the laser-produced Gd plasma EUV source development. In this paper, a dual-laser-pulse scheme, which uses a low energy pulse to produce a pre-plasma and a main pulse after a time delay to shoot the pre-plasma, is employed to mitigate the energetic ion generation from the source. Optimal conditions (such as pre-pulse energy and wavelength, and the time delay between the pre-pulse and the main pulse for mitigating the ion energy) are experimentally obtained, and with the optimal conditions, the peak of the ion energy is found to be reduced to 1/18 of that of a single laser pulse case. Moreover, the combined effect by applying ambient gas to the dual-pulse scheme for ion debris mitigation is demonstrated, and the result shows that the yield of Gd ions is further reduced to around 1/9 of the value for the case with dual laser pulses.
中图分类号: (Laser-plasma interactions)