Properties of amorphous hydrogenated carbon films from ArF laser-induced C2H2 photolysis

Abstract

Amorphous hydrogenated carbon films (a-C:H) have been deposited using 193-nm ArF laser-induced photolysis. The source gas was C2H2 (5%), diluted in argon (95%). The substrate temperature was varied between 150 and 350 °C in steps of 50 °C. Infrared spectroscopic analysis yields results on hydrogen content and sp3/sp2 carbon bond ratio. For the H/C atomic ratio values near 1.0 and for the sp3/sp2 bond ratio values near 10 are obtained. The corresponding values for plasma-deposited a-C:H films from C2H2 are distinctly lower. Electrical resistivity, refractive index, optical gap, and microhardness have also been determined.