Deposition of diamond-like carbon films by plasma source ion implantation with superposed pulse

Abstract Diamond-like carbon (DLC) films were prepared on silicon wafer substrate by plasma source ion implantation with superposed negative pulse. Methane and acetylene gases were used as working gases for plasma. A negative DC voltage and a negative pulse voltage were superposed and applied to the substrate holder. The DC voltage was changed in the range from 0 to −4 kV and the pulse voltage was changed from 0 to −18 kV. The surface of DLC films was very smooth. The deposition rate of DLC films increased with increasing in superposed DC bias voltage. Carbon ion implantation was confirmed for the DLC film deposited from methane plasma with high pulse voltage. I D / I G ratios of Raman spectroscopy were around 1.5 independent on pulse voltage. The maximum hardness of 20.3 GPa was observed for the film prepared with high DC and high pulse voltage.