Deposition of Fluorine-Containing Thin Film by Atmospheric Pressure Plasma Jet and Film Surface Structural Transition

Abstract

Plasma polymerized fluorine-containing (SiOxCyFz) thin films were deposited with an atmospheric pressure plasma jet, a useful technique to form thin films of fluorocarbon/silica nanohybrids. This atmospheric pressure plasma polymerization was fed with argon/1H,1H,2H,2H-perfluorooctyltriethoxysilane mixtures. AFM analysis found the nano-textured SiOxCyFz thin films obtained a high degree of surface roughness with an average size of 30 nm. FTIR and XPS found varying working distances in their chemical structure transitions. As the working distance increased, the fluorine compositions of the SiOxCyFz films increased from 12 to 50%, and at a greater working distance, the chemical structure of the atmospheric pressure plasma polymerized thin films was converted to the fluorine-containing dominion. The dielectric constant property of the SiOxCyFz thin film was examined by ellipsometry. From experimental results indicated, the decrease in the dielectric constant of the SiOxCyFz thin films can be attributed a decreased electronic polarization. This investigation demonstrates that the working distance of atmospheric pressure plasma polymerization affords good control of fluorine-containing film properties.