激光锡等离子体的状态参数分布和极紫外波段辐射的模拟研究  

Numerical simulation of state parameter distributions and extreme ultraviolet radiation in laser-produced tin plasma

作　　者：敏琦 王国栋 何朝伟 何思奇 卢海东 刘兴邦 武艳红 苏茂根 董晨钟 MIN Qi;WANG Guodong;HE Chaowei;HE Siqi;LU Haidong;LIU Xingbang;WU Yanhong;SU Maogen;DONG Chenzhong(Key Laboratory of Atomic and Molecular Physics&Functional Material of Gansu Province,College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,China;School of Computer Science and Artificial Intelligence,Lanzhou Institute of Technology,Lanzhou 730050,China)

机构地区：[1]西北师范大学物理与电子工程学院,甘肃省原子分子物理与功能材料重点实验室,兰州730070 [2]兰州工业学院计算机与人工智能学院,兰州730050

出　　处：《物理学报》2025年第3期1-15,共15页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12474279,12064040,12464036,12374384);中央引导地方财政专项(批准号:23ZYQA293)资助的课题。

摘　　要：激光锡(Sn)等离子体光源是当前先进极紫外(EUV)光刻机中最为核心的分系统,其辐射出的13.5 nm附近2%带宽内的EUV光的功率值和稳定性是决定整个光刻机是否成功的关键指标之一,本文针对激光Sn等离子体光源这一复杂系统,开展了详细的关于等离子体状态参数分布以及EUV辐射光谱的数值模拟研究.首先基于细致能级模型,在局域热动平衡近似条件下计算得到了Sn等离子体在12—16 nm波段的辐射不透明度数据.随后利用激光等离子体辐射流体力学程序RHDLPP,分别模拟了纳秒激光脉冲作用于Sn平面固体靶和液滴靶所产生的等离子体的温度和电子密度等状态参数的分布.结合辐射不透明度数据和等离子体状态数据,利用光谱模拟后处理子程序SpeIma3D完成了平面靶等离子体的空间分辨EUV光谱以及液滴靶等离子体在60°观测角下的角分辨EUV光谱的模拟.最后,得到了液滴靶等离子体在13.5nm,2%带宽内的带内辐射强度随观测角度的变化规律.本文获得的所有等离子体状态参数分布和EUV光谱模拟结果与现有的实验结果具有很好的一致性,证明了RHDLPP程序在激光Sn等离子体EUV光源方面的模拟能力,相关结果可以为EUV光刻以及国产化EUV光源的研制提供一定的支持.The laser-produced Sn plasma light source is a critical component in advanced extreme ultraviolet(EUV)lithography.The power and stability of EUV radiation within a 2%bandwidth centered at 13.5 nm are key indicators that determine success of the entire lithography process.The plasma state parameter distributions and the EUV radiation spectrum for a laser-produced Sn plasma light source are numerically simulated in this work.The radiative opacity of Sn plasma within the 12–16 nm range is calculated using a detailed-levelaccounting model in the local thermodynamic equilibrium approximation.Next,the temperature distribution and the electron density distribution of plasma generated by nanosecond laser pulses interacting with both a Sn planar solid target and a liquid droplet target are simulated using the radiation hydrodynamics code for laserproduced plasma,RHDLPP.By combining the radiative opacity data with the plasma state data,the spectral simulation subroutine SpeIma3D is employed to model the spatially resolved EUV spectra for the planar target plasma and the angle-resolved EUV spectra for the droplet target plasma at a 60-degree observation angle.The variation of in-band radiation intensity at 13.5 nm within the 2%bandwidth as a function of observation angle is also analyzed for the droplet-target plasma.The simulated plasma state parameter distributions and EUV spectral results closely match existing experimental data,demonstrating the ability of RHDLPP code to model laser-produced Sn plasma EUV light sources.These findings provide valuable support for the development of EUV lithography and EUV light sources.

关 键 词：极紫外光刻光源 激光锡等离子体 辐射流体力学程序 极紫外光谱 

分 类 号：TN249[电子电信—物理电子学] O53[理学—等离子体物理]