双脉冲激光锡等离子体光源的碎屑动力学研究

Research on the Dynamics of Ion Debris from Sn Plasma by Use of Dual Laser Pulses

极紫外光刻是下一代大容量集成电路制造中最有发展前景的技术之一,而碎屑的减缓及阻挡一直是极紫外光刻光源研究中亟需解决的关键问题。研究了双纳秒激光脉冲辐照锡靶产生的等离子体碎屑的动力学演化。结果表明,等离子体碎屑强烈依赖于预脉冲的能量及其与主脉冲的时间延迟,当预脉冲能量为30mJ,双脉冲时间间隔150ns情况下,大部分锡离子的能量从2.47keV降低到0.40keV,降低了6.1倍,碎屑得到了有效抑制。通过对碎屑动能角分布的测量,发现此方法可以有效减缓全角度范围的激光锡等离子体碎屑,并且越接近靶材法线方向,碎屑的动能减少得越多。

Extreme ultraviolet lithography is one of the most promising technologies on the next generation of high-capacity inte-grated circuit manufacturing .However ,techniques for ion debris mitigation have to be considered in the application of extreme ultraviolet source for lithography .In our paper the dynamics of ion debris from Sn plasma by using dual ns laser pulses were in-vestigated .The results show that debris from plasma greatly depends on the energy of pre-pulse and the delay time between the two laser pulses .The energy of Sn ions debris was efficiently mitigated from 2.47 to 0.40 keV in the case of dual laser pulses , up to 6.1 times lower than that by using single laser pulse .We also found that Sn ions debris can be mitigated at all angles by using the dual laser pulses method .