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

Abstract

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-on-disc 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.

Keywords:

• Amorphous carbon films
• Titanium carbide
• Radio frequency sputtering
• Nanostructure
• Lubrication

The authors are grateful to the National Natural Science Foundation of China (grant no. 50905177 and no. 50823008), the National 973 Project of China (grant no. 2007CB607601) and the Innovative Group Foundation from the National Natural Science Foundation of China (grant no. 50721062) for financial support.