Spectroscopic study of debris mitigation with minimum-mass Sn laser plasma for extreme ultraviolet lithography
Spectroscopic study of debris mitigation with minimum-mass Sn laser plasma for extreme ultraviolet lithography
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DOI：
10.1063/1.2199494
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发表时间：
2006-04-24
影响因子：
4
通讯作者：
Takiyama, K
中科院分区：
文献类型：
--
作者：
Namba, S;Fujioka, S;Takiyama, K
一项实验研究采用了由最小质量的纯锡 (Sn) 组成的靶材，以实现最高的极紫外 (EUV) 光转换，同时最大限度地减少等离子体碎片的产生。最小质量目标由涂在塑料壳上的薄锡层组成，并用 Nd:YAG 激光脉冲进行照射。通过空间分辨可见光谱研究了从 Sn 等离子体中发出的中性原子和单电荷离子的膨胀行为。随着 Sn 层厚度的减小，相对于入射激光束向后方向的碎片发射显着减少。研究发现，对于 7 x 10(10) W/cm(2) 的 9 ns 激光脉冲，Sn 层的最佳厚度为 40 nm，同时实现向后方向的低碎片发射和对 13.5 nm EUV 辐射的高转换。 (c) 2006 年美国物理研究所。
An experimental study was made of a target consisting of the minimum mass of pure tin (Sn) necessary for the highest conversion to extreme ultraviolet (EUV) light while minimizing the generation of plasma debris. The minimum-mass target comprised a thin Sn layer coated on a plastic shell and was irradiated with a Nd:YAG laser pulse. The expansion behavior of neutral atoms and singly charged ions emanating from the Sn plasma were investigated by spatially resolved visible spectroscopy. A remarkable reduction of debris emission in the backward direction with respect to the incident laser beam was demonstrated with a decrease in the thickness of the Sn layer. The optimal thickness of the Sn layer for a laser pulse of 9 ns at 7 x 10(10) W/cm(2) was found to be 40 nm, at which low-debris emission in the backward direction and a high conversion to 13.5 nm EUV radiation were simultaneously attained. (c) 2006 American Institute of Physics.