Silicon Oxide Coatings with Very High Rates (>10 nm/s) by Hexamethyldisiloxane-Oxygen Fed Atmospheric-Pressure VHF Plasma: Film-Forming Behavior Using Cylindrical Rotary Electrode

Silicon oxide films are deposited in atmospheric-pressure (AP) He/O 2 /HMDSO plasma excited by a 150 MHz VHF power using a cylindrical rotary electrode. The atomic bonding configurations and deposition rate are studied by controlling the O 2 concentration (O 2 /HMDSO source ratio) and VHF power density, the other parameters being maintained constant. Under the addition of 0.03 % O 2 to the process gas mixture (O 2 /HMDSO ≈ 0.09), AP-VHF plasma greatly enhances the fragmentation and oxidation of HMDSO, so that an almost inorganic film is obtained at a very high deposition rate of 33 nm s −1 . A silicon oxide coating on a polycarbonate pane is demonstrated with no significant thermal deformation of the pane, showing that AP-VHF plasma would be an efficient coating tool for polymer substrates.