Preparation and properties of metal-containing diamond-like carbon films by magnetron plasma source ion implantation

Fe-, Co-, Ni-, and Mo-containing diamond-like carbon (DLC) films were prepared on silicon wafer and glass substrates by a process combining reactive magnetron sputtering with plasma source ion implantation (PSII). Fe, Co, Ni, and Mo were used as targets for the sputter source. Ar/C2H2 mixed gas was introduced into the discharge chamber. A negative high-voltage pulse (−10 kV, 100 Hz, 100 μs) was applied to the substrate holder. The chemical composition of the films was determined using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The surface morphology was observed by scanning electron microscopy (SEM). The film structure was characterized by Raman spectroscopy and X-ray diffractometry (XRD). The sheet resistivity of the films was measured by a four-point probe method. Furthermore, a ball-on-disc test was employed to obtain information about the frictional properties and sliding wear resistance of the films. The structure of the films changed from metal-containing DLC to composites of metal-containing DLC and metal carbides with increasing metal content in the films. The sheet resistivity of the films decreased drastically with increasing metal content in the films. The tribological properties of the films were improved by Mo doping.