Effect of positive pulses on the microstructure and mechanical properties of diamond-like carbon films deposited by PBII

In the present study, diamond-like carbon (DLC) films were deposited on steel and silicon substrates using a plasma based ion implantation (PBII) with bipolar pulses, and the effect of the positive pulse power on the properties of DLC films was investigated. The positive pulse voltage was varied from 2.0 to 6.3 kV while the negative pulse voltage was maintained at 5.0 kV. We obtained DLC films with a very low internal stress less than 0.5 GPa and a relatively high hardness greater than 22 GPa. The optimum deposition conditions for high deposition rate due to high plasma density and low friction exist, which are determined by the bipolar pulse power and surface temperature of substrate.