Development of gas-injected pulsed plasma CVD method using Ar/C₂H₂ mixed gas for ultra-high-rate diamond-like carbon deposition

Abstract A diamond-like carbon (DLC) fabrication method with a greater deposition rate and simple equipment configuration facilitates to introduce DLC coating technology to industrial processes. In this study, a gas-injected pulsed plasma CVD method using a single plasma source is proposed as an ultra-high-rate deposition method for DLC films. A gas mixture of Ar and C2H2 was injected into a vacuum chamber through a gas nozzle, and plasma in the chamber was generated by applying a negative pulse voltage to the substrate stage. The gas velocity in the chamber was calculated using computational fluid dynamics simulations. DLC films with a nanoindentation hardness of 17.5 GPa were fabricated on a limited area of a Si substrate at a deposition rate of 2480 nm min−1. The deposition rate of the DLC films can be further improved by optimizing the conditions of the Ar partial pressure ratio, gas velocity, and stage applied voltage.