Effects of Substrate Temperature on Film Hardness and Hydrogen Content in Diamond-like Carbon Films Prepared with a Repetitive Nanosecond Pulsed Glow Hydrogen/Methane Discharge Plasma

Abstract

A repetitive nanosecond pulsed glow hydrogen/methane discharge plasma generated at 1.2 kPa gas pressure led to diamond-like carbon films with high hardness and a high-speed deposition rate of 0.13 µm/min. Film hardness showed strong substrate temperature dependence, reaching up to 15 GPa. Raman spectroscopy revealed that hydrogen content in the films decreased with increasing substrate temperature. The mechanisms of the changes in film hardness and hydrogen content are considered to be the substrate temperature dependence of the hydrogen abstraction reaction and etching by irradiation with hydrogen radicals.