预电离效应对ArF准分子激光特性的影响分析

Effects of Pre-ionization on Properties of ArF Excimer Laser

摘要:

利用流体模型对ArF准分子激光气体放电过程进行了数值模拟,通过对比不同初始预电离强度下的气体放电情况,分析了预电离效应对准分子激光系统放电特性的影响,并探究了不同气体参数下的预电离效果。结果表明,初始预电离强度对于极间击穿电压、ArF准分子的形成以及光输出特性均有显著影响。在保证均匀电场且有效放电的情况下,低的初始预电离强度难以“点燃”气体,但可以获得较高的激光输出能量,而提高初始预电离强度能有效降低击穿电压,却不利于气体对能量的吸收转化。此外,预电离效果受工作气压与F₂比例的影响,气压的升高或F₂浓度的增加,均会降低预电离的有效性。

Abstract:

A fluid model is used to investigate the discharge kinetics of ArF excimer laser. By comparing the gas discharge at different initial preionization intensities, the effects of preionization on discharge excited excimer laser system are analyzed. The preionization effect under different gas parameters is also discussed. The results show that the initial preionization intensity has significant effects on the breakdown voltage, the formation of ArF excimer, the optical quality and gain. Under the premise of uniform electric field and effective discharge, it is difficult to reach the gas breakdown threshold with low initial preionization intensity, but higher laser power can be obtained. Increasing the initial preionization intensity can effectively reduce the breakdown voltage, but it’s not conducive to the absorption and conversion of energy. The preionization capability is affected by the gas pressure and fluorine ratio. The increasing of gas pressure or fluorine concentration can reduce the effectiveness of preionization.