Physical properties of carbon films obtained by methane pyrolysis in an electric field

A method of synthesizing carbon films on single-crystal silicon substrates by methane pyrolysis in an electrical field is suggested. The pressure and temperature arising in a working chamber when the substrate is exposed to C$^{-4}$ ions during pyrolysis are measured. Ion bombardment generates nuclei in the form of fibers about 2 $\mu$m in diameter providing the growth of a polycrystalline film. The resulting material is examined using electron microscopy and photo- and cathodoluminescence. Synthesized films are a composite material the matrix of which contains nanoclusters of a dissimilar crystalline nature. The effect of considerable two-stage decrease in the resistivity of the film material with increasing temperature from 300 to 1750 K is discovered. This points to the semiconducting properties of thick carbon films.