Effect of dilution gases in methane on the deposition of diamond-like carbon in a microwave discharge II: Effect of hydrogen

Abstract

The effect of hydrogen as a dilution gas on the deposition of diamond-like carbon by the decomposition of methane in a microwave discharge was studied from surface analysis of the substrate and from plasma diagnostics. When carbon deposited from a CH4-Ar plasma and consisting of large amounts of graphite and small amounts of diamond, was placed in the hydrogen plasma chemical sputtering of carbon to form hydrocarbons and adsorption of hydrogen on the carbon substrate were observed. The reaction occured only on graphite and not on diamond. The effects of hydrogen as a dilution gas on the deposition of diamond-like carbon from CH4-H2 plasma are to cause the formation of CH3 radicals in the plasma, the removal of graphite from the deposit and the adsorption of atomic hydrogen on the deposit as an active participant in the diamond crystallization process.