Microstructure and properties of nc-TiC/a-C:H films deposited by radio frequency reactive sputtering

Amorphous carbon films containing titanium carbide (nc-TiC/a-C:H) were deposited onto n-type silicon (100) by radio frequency reactive sputtering titanium target in an Ar-CH₄ mixed atmosphere. The composition and microstructure of the films were characterised by means of X-ray photoelectron spectroscopy, field emitted SEM, XRD and Raman spectra. The mechanical and tribological properties of the films were measured by a nanoindentation tester and a ball-ondisc UMT-2MT tribometer. By adjusting the CH₄ flowrate, Ti content in the films could be controlled, and a transition in structures of the films from loose polymer-like to glassy and dense nanostructure was observed. The density of coatings was improved by the introduction of TiC nanocrystalline particles. The mechanical and lubricious properties were different accordingly.