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Journal of University of Chinese Academy of Sciences ›› 2025, Vol. 42 ›› Issue (4): 441-449.DOI: 10.7523/j.ucas.2023.064

• Research Articles • Previous Articles    

Molecular dynamics study of the interaction between Ar atom and graphite

WU Wei, YU Xin   

  1. School of Engineering Sciences,University of Chinese Academy of Sciences,Beijing 100049, China
  • Received:2023-03-29 Revised:2023-05-23

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

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