Energy spectra and charge states of debris emitted from laser-produced minimum mass tin plasmas

被引：5

作者：

Fujioka, Shinsuke ^{[1
]}

Nishimura, Hiroaki ^{[1
]}

Ando, Tstiyoshi ^{[1
]}

Ueda, Nobuyoshi ^{[1
]}

Namba, Shinichi ^{[2
]}

Aota, Tatsuya ^{[1
]}

Murakami, Masakatsu ^{[1
]}

Nishihara, Katsunobu ^{[1
]}

Kang, Young -G. ^{[1
]}

Sunahara, Atsushi ^{[3
]}

Furukawa, Hiroyuki ^{[3
]}

Shimada, Yoshinori ^{[3
]}

Hashimoto, Kazuhisa ^{[3
]}

Yamaura, Michiteru ^{[3
]}

Yasuda, Yuzuri ^{[1
]}

Nagai, Keiji ^{[1
]}

Norimatsu, Takayoshi ^{[1
]}

Miyanaga, Noriaki ^{[1
]}

Izawa, Yasukazu ^{[1
]}

Mima, Kunioki ^{[1
]}

机构：

[1] Osaka Univ, Inst Laser Engn, 2-6 Yamadaoka, Suita, Osaka, Japan

[2] Hiroshima Univ, Grad Sch Engn, Higashihiroshima, Hiroshima 7398527, Japan

[3] Inst Laser Technol, Suita, Osaka, Japan

来源：

EMERGING LITHOGRAPHIC TECHNOLOGIES X, PTS 1 AND 2 | 2006年 / 6151卷

关键词：

extreme ultraviolet; laser-produced plasma; debris; minimum mass target; punch-out scheme;

D O I：

10.1117/12.656071

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

Laser-produced Sn plasma is an efficient extreme ultraviolet (EUV) light source, however the highest risk in the Sn-based EUV light source is contamination of the first EUV collection mirror caused by debris emitted from the Sn plasma. Minimum mass target is a key term associated with relaxation of the mirror contamination problem. For design of the optimum minimum mass Sn target, opacity effects on the EUV emission from the laser-produced Sn plasma should be considered. Optically thinner plasma produced by shorter laser pulse emits 13.5 nm light more efficiently; 2.0% of conversion efficiency as experinientally attained with drive laser of 2.2 ns in pulse duration, 1.0 x 10(11) W/cm(2) in intensity. and 1.064 mu m in wavelength. Under the optimum laser conditions, the minimum mass required for sufficient EUV emission, which is also affected by the opacity, is equal to the product of the ablation thickness and the required laser spot size. Emission properties of ionized and neutral debris from laser-produced minimum mass Sn plasmas have been measured with particle diagnostics and spectroscopic method. The higher energy ions have higher charge states, and those are emitted from outer region of expanding plasmas. Feasibility of the minimum mass target has been demonstrated to reduce neutral particle generation for the first time. In the proof-of-principle experiments, EUV emission from a punch-out target is found to be comparable to that from a static target, and expansion energy of ion debris was drastically reduced with the use of the punch-out target.

引用

页码：U1525 / U1534

页数：10

共 38 条

[11] Efficient soft x-ray emission source at 13.5 nm by use of a femtosecond-laser-produced Li-based microplasma [J].