Study of the 6.x nm short wavelength radiation spectra of laser-produced erbium plasmas for BEUV lithography

作     者：吴涛 王倩 陈柳安 陆培祥 Tao WU;Qian WANG;Liuan CHEN;Peixiang LU

作者机构：Hubei Key Laboratory of Optical Information and Pattern RecognitionSchool of Optical Information and Energy EngineeringWuhan Institute of TechnologyWuhan 430205People's Republic of China Guangdong Intelligent Robotics InstituteDongguan 523808People's Republic of China 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2023年第25卷第6期

页      面：41-51页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 070204[理学-等离子体物理] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：support from Guangdong Major Project of Basic and Applied Basic Research(No.2019B030302003) 

主　　题：laser-produced plasmas unresolved transition array collisional radiative equilibrium 

摘      要：Beyond extreme ultraviolet(BEUV)radiation with a wavelength of 6.x nm for lithography is responsible for reducing the source wavelength to enable continued miniaturization of semiconductor *** this work,the Required BEUV light at 6.x nm wavelength was generated in dense and hot Nd:YAG laser-produced Er *** spectral contributions from the 4p–4d and 4d–4f transitions of singly,doubly and triply excited states of Er XXIV–Er XXXII in the BEUV band were calculated using Cowan and the Flexible Atomic *** was also found that the radiative transitions between multiply excited states dominate the narrow wavelength window around 6.x *** the assumption of collisional radiative equilibrium of the laser-produced Er plasmas,the relative ion abundance in the experiment was *** the Boltzmann quantum state energy level distribution and Gram–Charlier fitting function of unresolved transition arrays(UTAs),the synthetic spectrum around 6.x nm was finally obtained and compared with the experimental *** spatio-temporal distributions of electron density and electron temperature were calculated based on radiation hydrodynamic simulation in order to identify the contributions of various ionic states to the UTAs arising from the Er plasmas near 6.x nm.