高气压激光维持氩等离子体实验与仿真  

Experimental and Computational Study of Laser-Maintained Argon Plasma under High Pressure

作　　者：王大智 袁博文 卢琪 乔俊杰 熊青 Wang Dazhi;Yuan Bowen;Lu Qi;Qiao Junjie;Xiong Qing(State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing University,Chongqing,400044,China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆400044

出　　处：《电工技术学报》2023年第9期2541-2554,共14页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(11975061,52111530088)。

摘　　要：激光维持等离子体(LSP)作为一种先进光源,具有高稳定性、宽光谱和高亮度的特点,应用价值高且广泛,例如基于LSP深紫外辐射的半导体表面高灵敏缺陷检测。LSP源的深紫外辐射产生过程及优化一直备受关注,实际测量较困难且有局限。该文以氩气LSP(气压>10^(6) Pa)为例,结合实验光谱测量及零维全局模型,探究了氩气LSP自持放电过程,获取了准分子Ar_(2)^(*)的主要产生及消失路径,并研究了氩气气压与激光功率对Ar_(2)^(*)的影响机制,基于此预判了气压与激光功率对Ar_(2)^(*)126 nm深紫外辐射的优化趋势,指出提高气体压强是增强126 nm辐射强度的一种经济且有效的方式。Laser-sustained plasma(LSP),as an advanced light source,has the characteristics of high stability,wide spectrum,and high brightness which has value in applications like highly sensitive defect detection of semiconductor surface based on LSP vacuum ultraviolet radiation.The generation process and optimization of the vacuum ultraviolet radiation produced by the LSP source have always attracted much attention.Based on the experimental spectral measurement and zero-dimensional global simulation model,this paper explored the self-sustaining discharge process of argon LSP(pressure>10 bar),the main generation and disappearance path of Ar_(2)^(*),and the mechanism of argon gas pressure and laser power on Ar_(2)^(*).Based on these works,the optimization trend of Ar_(2)^(*)126 nm vacuum ultraviolet radiation was predicted.An LSP generator in high-pressure pure argon environment was designed and constructed.The experimental conditions were divided into 11 groups according to argon pressure and laser power.It was observed that the brightness of Ar LSP decreased after the ignition power was turned off,which was caused by the process of electrons loss due to recombination of free electrons with Ar ions.In addition,with the increase of laser power(123~201 W)and Ar pressure(13~20 bar),the relative intensity of the LSP emission spectrum increased significantly.Combined with the experimental results,a zero-dimensional global model of argon LSP containing 23 kinds of particles and 326 reactions was established,the laser power and Ar pressure were coupled with particle density and temperature parameters.The particle number density generated in the model was calculated in balance.The simulated radiation spectrum of LSP is obtained based on emission spectroscopy theory,and is in good agreement with the experimental spectrum.The simulation time started from the electrode was powered off to the stable Ar LSP phase.The time evolution behavior of each particle under typical working conditions(laser power 201 W,argon pressure 14 bar)was di

关 键 词：激光维持等离子体 真空紫外辐射 光谱测量 零维模型 Ar_(2)^(*)分子 

分 类 号：O539[理学—等离子体物理] TM213[理学—物理]