不同缓冲气体中ArF准分子激光系统放电特性分析  

Analysis of ArF excimer laser system discharge characteristics in different buffer gases

作　　者：王倩[1,2,3] 赵江山 范元媛 郭馨 周翊 Wang Qian;Zhao Jiang-Shan;Fan Yuan-Yuan;Guo Xin;Zhou Yi(Institute of Microelectronics of Chinese Academy of Sciences,Beijing 100094,China;Beijing Excimer Laser Technology and Engineering Center,Beijing 100094,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Applied Optics,Changchun 130033,China)

机构地区：[1]中国科学院微电子研究所,北京100094 [2]北京市准分子激光工程技术中心,北京100094 [3]中国科学院大学,北京100049 [4]应用光学国家重点实验室,长春130033

出　　处：《物理学报》2020年第17期127-134,共8页Acta Physica Sinica

基　　金：国家科技重大专项(批准号:2013ZX02202);应用光学国家重点实验室开放基金(批准号:SKLAO-201915)资助的课题.

摘　　要：为深入理解挖掘ArF准分子激光系统运转机制,进而获得ArF准分子激光系统设计优化的理论及方向性指导,文章基于流体模型,以气体高压放电等离子体深紫外激光辐射过程为主要研究对象,研究了放电抽运ArF准分子激光系统的动力学特性,分析了不同缓冲气体中,ArF准分子激光系统极板间电压、电流、光子数密度变化趋势及电子数密度空间分布情况,讨论了光电离在系统放电过程中的重要作用.结果表明,Ne作为缓冲气体时,电子耗尽层及阴极鞘层宽度更小,放电更加稳定.在Ne中添加杂质气体Xe,可以通过光电离加速放电区域的扩展,减小电子耗尽层及阴极鞘层的宽度,降低放电发生的阈值电压,提高放电稳定性.Excimer laser is the current mainstream source of international semiconductor lithography.The stable operation of the laser system directly affects the working efficiency of the semiconductor lithography machine,so it is very important to optimize the laser system.The buffer gas commonly used in ArF excimer laser systems is He,Ne.In the early years,Shinjin Nagai and Mieko Ohwa have studied the output characteristics of the system when using He or Ne as a buffer gas from the aspect of pump efficiency and gain coefficient,and pointed out that using Ne instead of He has no obvious advantages in terms of efficiency.However,when Ne is used as the buffer gas,the reaction between Ne and electrons is more complicated.In addition to direct ionization and excitation reactions,it also contains a large amount of step ionization and secondary ionization,which releases free electrons.The stability of the system is improved,when Ne is used as the buffer gas.The ArF excimer laser system discharge characteristics in different buffer gases are analyzed based on fluid model in the paper.The role of photoionization is discussed.The simulation results show that the width of the electron depletion layer and the cathode sheath are both smaller,and the discharge stability is higher when Ne is used as the buffer gas.The expansion of the discharge region is accelerated and the threshold voltage of the discharge is reduced by adding Xe into Ne to trigger photoionization.The excimer laser discharge process is very complicated and is affected by many factors.Only two factors of the buffer gas and the photoionization process are studied in this paper.The simulation model will be extended from one-dimensional case to two-dimensional case in the future,and multiple physical factors of the ArF excimer laser system will be considered.

关 键 词：ArF准分子激光 流体模型 电子数密度 光电离 

分 类 号：O461[理学—电子物理学] TN249[理学—物理]