A SIMPLIFIED SPHERICAL-SYMMETRY SIMULATION MODEL FOR THE GENERATION OF 13.5-NM EXTREME ULTRAVIOLET SOURCE BY LASER-PRODUCED PLASM

• Main Authors: Yi-Ping Lai, 賴奕蘋
• Other Authors: Sheng-Lung Huang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/89673501435923070852

碩士 === 國立臺灣大學 === 光電工程學研究所 === 100 === The development of compact and high efficiency extreme ultraviolet (EUV) light sources have evolved from academic researches to industrial applications, e.g. metrology and lithography et al. The EUV light sources based on the laser-produced plasma attract researchers'' attention due to its power scalability and spatial coherence. The plasma-based system is too complicated to be theoretically analyzed, so the computer simulation becomes indispensible. However, it is very complicated and computationally intensive to model the whole EUV generation process, which includes comprising seed ionization, plasma formation, and EUV emission. Here we present a simplified spherical-symmetric simulation model for the generation of 13.5 nm extreme ultraviolet source by laser-produced plasma with the experimental bench marks to make the simulation tool more accessible and easier. The model is achieved by revising the one-dimensional hydrodynamic code MED103 so that arbitrary laser pulse shape and more simulation cells can be considered and coupling the collision-radiative equilibrium equations to calculate the ion charge state distributions. In addition, in-band emission of 13.5±2% nm is estimated according to the contributions from the weighted oscillator strengths of Sn8+~Sn13+. The simulated temporal and spatial evolution of plasma density, electron temperature, EUV emission profile, and ion charge states for 1064-nm laser and tin-doped droplet target will be presented in the paper. The influences of laser duration, pulse shape, dopant density, and target diameter on EUV characteristics were examined discussed in the paper.