极紫外光刻动态气体锁抑制率的理论研究

Theoretical Investigation on Suppression Ratio of Dynamic Gas Lock for Extreme Ultraviolet Lithography

从理论上系统性地研究了动态气体锁抑制率,提出了动态气体锁理论分析模型。通过理论分析推导出单组分和多组分清洁气体在等截面或者变截面条件下的动态气体锁抑制率解析表达式,并对单组分清洁气体在等截面和变截面条件下的动态气体锁抑制率进行了比较。研究结果表明,当抑制率为85%以上时,可以近似地使用等截面假设来计算动态气体锁抑制率,且应以清洁气体出口处截面面积作为动态气体锁平均截面面积;动态气体锁抑制率与动态气体锁结构以及清洁气体相关量值有关,当给定动态气体锁结构和扩散系数时,动态气体锁抑制率随着向硅片台腔室扩散的气体体积流量的增大而增大。该动态气体锁抑制率理论研究体系,能够为极紫外(EUV)光刻机动态气体锁的研制提供理论依据。

The theory of dynamic gas lock （DGL） suppression ratio is systematically studied and the DGL theoretical model is provided. Then the suppression ratio formulas of DGL with uniform or variable sections are derived through theoretical calculation under the conditions of single- or multi-component purge gases. Moreover, the suppression ratios of uniform-section DGL and variable-section DGL are compared for single-component purge gas. The theoretical results show that the uniform-section supposition, taking the section area where purge gas flows out DGL as the average section area, can be used when the suppression ratio is more than 85 ~//00 ; the suppression ratio is related to the DGL structure and the parameters of purge gas, and the suppression ratio increases with the increase of the gas volume flux into the wafer chamber when the DGL structure and diffusion coefficient are constant. The theory system proposed on DGL suppression ratio can provide a theoretical basis for the development of DGL in the extreme ultraviolet （EUV） lithography.