Ultra-high-rate deposition of diamond-like carbon films using Ar/C2H2 plasma jet CVD in combination with substrate-stage discharge

Diamond-like carbon (DLC) films with excellent mechanical properties are used as functional surface protective films for cutting tools. The deposition rate of DLC films using conventional plasma chemical vapor deposition (CVD) methods is several hundred nm min(-1). This study applied a negative DC pulsed voltage to a substrate stage irradiated with an Ar/C2H2 mixed plasma jet. The effect of the voltage applied to the stage on the fabricated DLC films was investigated based on the thicknesses and characteristics of the films. DLC films were formed on Si substrates using an Ar/C2H2 plasma jet CVD system. Ar plasma was ejected from a circular nozzle, and C2H2 gas was supplied as a carbon source gas from the center of the circular nozzle. DLC films with a nanoindentation hardness of 17 GPa were obtained by applying -500 V to the stage with a deposition rate of 2140 nm min(-1).