Evolution analysis of EUV radiation from laser-produced tin plasmas based on a radiation hydrodynamics model.
Evolution analysis of EUV radiation from laser-produced tin plasmas based on a radiation hydrodynamics model.
复制标题
基于辐射流体动力学模型的激光产生的锡等离子体的 EUV 辐射的演化分析
DOI：
10.1038/srep45212
复制
发表时间：
2017-03-23
影响因子：
4.6
通讯作者：
Dong CZ
中科院分区：
文献类型：
--
作者：
Su MG;Min Q;Cao SQ;Sun DX;Hayden P;O'Sullivan G;Dong CZ
极紫外(EUV)光刻的基本目标之一是最大化激光能量对特定元素的激光等离子体(LPP)在特定波长的辐射的亮度或转换效率，以匹配现有的多层光学系统。TiN LPP被选为在13.5 nm波长下工作。为了研究激光产生的TiN等离子体的EUV辐射，研究相关的原子过程及其演化，以便可靠地预测最佳的等离子体和实验条件是至关重要的。本文基于流体动力学方程和辐射传输方程，提出了一个简化的辐射流体力学模型，用于快速研究激光产生的TiN等离子体中辐射性质和动力学的演化。成功地模拟和解释了与等离子体膨胀方向成45°夹角测量的EUV光谱的自吸收特性，并对等离子体温度、离子分布和密度、膨胀尺寸和速度等参数的演化进行了评价。我们的研究结果将有助于进一步理解目前在光刻、计量学和生物成像等应用领域开发极端紫外线和软X射线源的研究。
One of fundamental aims of extreme ultraviolet (EUV) lithography is to maximize brightness or conversion efficiency of laser energy to radiation at specific wavelengths from laser produced plasmas (LPPs) of specific elements for matching to available multilayer optical systems. Tin LPPs have been chosen for operation at a wavelength of 13.5 nm. For an investigation of EUV radiation of laser-produced tin plasmas, it is crucial to study the related atomic processes and their evolution so as to reliably predict the optimum plasma and experimental conditions. Here, we present a simplified radiation hydrodynamic model based on the fluid dynamic equations and the radiative transfer equation to rapidly investigate the evolution of radiation properties and dynamics in laser-produced tin plasmas. The self-absorption features of EUV spectra measured at an angle of 45° to the direction of plasma expansion have been successfully simulated and explained, and the evolution of some parameters, such as the plasma temperature, ion distribution and density, expansion size and velocity, have also been evaluated. Our results should be useful for further understanding of current research on extreme ultraviolet and soft X-ray source development for applications such as lithography, metrology and biological imaging.