Effects of Si content in DLC films on their friction and wear properties

Without TMS flow, the friction coefficients (FCs) were the largest, 0.35, and the DLC film came off easily. With the increase of TMS flow up to 1.0 sccm, the FC decreased to 0.14, and there was almost no peeling off. For 2.0 sccm, the FC was 0.18, and there was a lot of debris on the DLC surface. Hardness gradually decreased with the increase of TMS flow up to 1.0 sccm, and it decreased drastically for high flow rates or high Si content. Internal stress (compressive) of the films decreased with the increase of TMS flow. Si content in the film corresponded almost linearly to the TMS flow rate. One to two percent of Si doping is very suitable for improving the adhesion of films and reducing internal stress while maintaining the surface hardness of DLC films.