Reaction analysis and the removal mechanism of organic contaminants in plasma cleaning: a molecular dynamics simulation

A large-aperture pulse-compression grating is one of the key components for laser-driven inertial confinement fusion, and is extremely vulnerable to being damaged by volatile organic contamination during operation. Plasma cleaning technology is a prospective method for removing organic deposits on the surface of optical components. Dibutyl phthalate, a commonly used sealing material, is used as the contamination source in this study, and the method of reactive molecular dynamics is used to simulate the plasma-based removal process of organic contaminants. The effects of key plasma cleaning parameters are investigated, including the interaction time, particle incident energy, and reactive species. Different mechanisms of nitrogen and oxygen plasma interactions were investigated. The effect of plasma on chemical bond fracture was analyzed, and the synergistic effect of physical and chemical influences was considered. The decomposition pathways and removal mechanism of organic contaminants under different incident reactive species are proposed at the atomic level. DBP clusters were removed by nitrogen and oxygen plasma. The effects of the incidence duration, particle energies, and particle types on the decomposition were investigated. Decomposition pathways were further confirmed by bond dissociation energies.