Deposition of diamond-like carbon films using plasma based ion implantation with bipolar pulses

Plasma based ion implantation (PBII) with bipolar pulses has been proposed to improve a dose uniformity in an ion implantation on a three-dimensional target. A pulsed glow discharge plasma is produced around the target by a positive pulse at a gas pressure less than ∼0.5 Pa, and then ions are implanted into the target from all sides by the subsequent negative high-voltage pulse. It has been shown that ions produced by the positive pulse have been implanted effectively with the negative pulse. The PBII with bipolar pulses is applied to DLC coatings. A carbon mixing layer in the substrate surface is formed by the implantation to improve the adhesion of DLC films. Internal stress of DLC films slightly decreases with increasing frequencies of positive pulse. Moreover, it is shown that the PBII with bipolar pulses is possible to use for inner coating of DLC films on a stainless-steel pipe.