Effects of substrate bias on tribological properties of diamondlike carbon thin films deposited via microwave-excited plasma-enhanced chemical vapor deposition

In this study, the structure and tribological performance of the diamondlike carbon (DLC) films were related to deposition parameters. The feasibility of the microwave-excited plasma-enhanced chemical vapor deposition (μW-PECVD) as a process to produce good quality DLC films was the focus. The DLC films were deposited on the steel substrates with a tungsten carbide interlayer via μW-PECVD. The negative substrate bias used during the film deposition was varied. The Raman results revealed that the increased negative substrate bias increased the sp3 bonding in the DLC films as a result of the increased kinetic energy of film-forming ions during the film deposition. The tribological results clearly indicated that the friction and wear of the DLC-coated steel samples against a 100Cr6 steel ball significantly decreased with increased negative substrate bias due to the significantly improved wear resistance of the DLC films