Ar原子与石墨片层相互作用的分子动力学研究

doi:10.7523/j.ucas.2023.064

摘要/Abstract

摘要： 在EUV(extreme ultraviolet)光刻机中，多层膜反射镜在暴露于高能EUV辐射下会产生碳(C)沉积等污染，严重降低反射镜的反射率以至于降低光刻机的使用寿命。而EUV光对背景气体电离产生的EUV诱导等离子体对沉积碳有着较好的清洁作用。采用分子动力学方法对EUV诱导氩(Ar)等离子体与石墨状沉积碳的相互作用过程进行模拟，从Ar在石墨表面的吸附到大量Ar原子对石墨表面累计辐照进行研究。结果表明，Ar在石墨表面Hollow位点具有最稳定的吸附结构，当Ar在石墨表面扩散时倾向穿过C—C键中间的Bridge点向相邻Hollow点扩散。单个独立载能Ar在入射到石墨表面时会产生反射、吸附和扩散3种现象，这主要与Ar原子入射到石墨的位点有关。而当大量Ar累计辐照石墨时，根据入射Ar数量和能量的增多会产生多种缺陷并不断发展，使石墨层的强度大大减弱并产生物理溅射效果。

关键词: 分子动力学, EUV等离子体, 石墨, 碳清洁

Abstract: In EUV(extreme ultraviolet) lithography machines, multilayer mirrors may be contaminated by carbon deposition when exposed to high-energy EUV radiation. The reflectivity of the mirror is therefore reduced, thereby reducing the service life of the lithography machine. The EUV induced plasma produced by the ionization of the background gas by EUV light has a good cleaning effect on the deposited carbon. In this paper, molecular dynamics method is used to simulate the interaction process between Ar ions of plasma and graphitic deposited carbon. A comprehensive study has been carried out from the adsorption of Ar on the graphite surface to the cumulative irradiation of independent Ar and a large amount of Ar on the graphite surface. The results show that Ar has the most stable adsorption structure at the Hollow site on the graphite surface. When Ar diffuses on the graphite surface, it tends to diffuse through the Bridge site in the middle of the C-C bond to the adjacent Hollow site. When a single independent energetic Ar impinges on the surface of graphite, there would be three phenomena: reflection, adsorption and diffusion. It mainly depends on the site of incident Ar on the graphite. When a large amount of Ar accumulatively irradiates graphite, a variety of defects will occur and continue to develop depending on the amount and energy of incident Ar. As a result, the strength of the graphite layer is greatly reduced and even physical sputtering effects occur.

Key words: molecular dynamics, EUV induced plasma, graphite, carbon cleaning

中图分类号:

O369

吴伟, 余新刚. Ar原子与石墨片层相互作用的分子动力学研究[J]. 中国科学院大学学报, 2025, 42(4): 441-449.

WU Wei, YU Xin. Molecular dynamics study of the interaction between Ar atom and graphite[J]. Journal of University of Chinese Academy of Sciences, 2025, 42(4): 441-449.

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