Effect of Sputtering Gas Species and Magnetic Field Strength on the Mechanical and Wear Properties of DLC Films Deposited by HiPIMS

The high-power impulse magnetron sputtering (HiPIMS) is a deposition method that has potential to achieve both high hardness and high surface smoothness of diamond-like carbon (DLC) films, and investigation has been performed to optimize the deposition process. However, the dominant HiPIMS process factors that affect the hardness and wear properties of DLC films have not been clarified based on the observation of plasma properties. In this study, we focused on the sputtering gas species that affect the densities of carbon ions in the plasma and the target magnetic field strength, which affects the ion transportation and its incident flux onto the deposition substrate. The results of this investigation reveal that the addition of neon to the conventional sputtering gas of argon promoted carbon ionization and the incident carbon ion flux on to the substrate was increased by suppressing the back attraction of carbon ions to the target in a weak magnetic field strength. It was also confirmed that these effects could potentially improve the hardness and wear properties of DLC films.