OPEN-AIR DEPOSITION OF SIO2 FILM FROM A COLD-PLASMA TORCH OF TETRAMETHOXYSILANE-H2-AR SYSTEM

A rf plasma beam was generated in the stream of atmospheric pressure argon to be exhausted from a cylindrical nozzle into air. The temperature measurements indicate a nonequilibrium low temperature nature of this plasma. By using this cold plasma torch, films were deposited on the substrates placed in air at growth rates higher than 100 angstrom/s by feeding tetramethoxysilane into the plasma. Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy revealed that the films were essentially SiO2 and their structures and properties could be improved by admixing hydrogen in the plasma. The SiO2 films deposited at a rate of 120 angstrom/s from Si(OCH3)4-H-2-Ar plasma had surfaces as smooth and hard as Coming 7059 glass.