SiO2-like film deposition on copper surface by atmospheric pressure diffuse discharge

Diffuse discharge can generate large-scale volume discharges at atmospheric pressure1, which could be used in surface modification of metal. In this paper, the feasibility of SiO2-like film deposition on copper surface by atmospheric pressure diffuse discharge is achieved. The diffuse discharge is driven by a microsecond-pulse power supply in a point-to-plate electrode configuration, and HMDSO (the precursor) is directly injected into the discharge region together with gas flow of Ar/air. The chemical composition of Cu surface before and after deposition is analyzed by fourier transform infrared spectroscopy (FTIR). Experimental results show that there is a intense peak at 1060 cm−1, which indicates SiO2-like coatings have been successfully deposited on the copper surface. Furthermore, lower HMD SO concentration can contribute to a better deposition with lower carbon content in the experiments. Moreover, surface morphology and thickness of the deposited film are also observed by atomic force microscope (AFM). The result shows that high amplitude of the applied voltage suppresses the increase of the thickness of the deposition film, but it is benefit to obtain a smooth surface. Such phenomenon can be explained by the etching of high-energy particles in plasmas. In summary, atmospheric-pressure diffuse discharge is a promising way to deposit SiO2-like film on metal surface.