Characterization of a-C:H Films Deposited on Dielectric Substrates by Atmospheric Pressure Surface Spark Discharge

摘要

Results of investigations of properties of amorphous hydrogenated (a-C:H) films deposited on dielectric substrates by atmospheric pressure surface spark discharge in methane which enables coatings to be deposited with high rates of growth (up to 100 μm/ h) onto large-area substrates are presented. The films are characterized by increased hardness (up to 3 GPa) and high transmittance in the visible range (α～10{sup}4-10{sup}5m{sup}(-1)); therefore they can be used as protective coatings on components made of soft and transparent plastics, The deposited a-C:H films consist of spherical granules, 20-50 nm in diameter, formed in gas in the spark channel and then deposited onto the substrate. A model of a-C:H film formation in atmospheric pressure surface spark discharge in methane based on a thermo-dynamic-equilibrium description of the gas phase is suggested which allows sufficiently good agreement between calculated and experimental data over the entire range of specific energies delivered per CH{sub}4 molecule investigated.