Diamond-like carbon (DLC) films were deposited by plasma decomposition of CH4/H2 gas mixtures in a RF glow discharge reactor. The chemical structure of diamond-like carbon films deposited at different bias voltages and CH4 flow contents was investigated by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. An indirect evaluation on the sp3-bonded carbon in the DLC films was made based on the structural information on the sp2-bonded carbon obtained from Raman measurements. The mechanical properties of DLC films deposited at different CH4 flow contents are discussed in terms of Raman parameters such as the position, width and integrated intensities of Raman D and G peaks. The friction coefficient of DLC films was obtained and their frictional behavior was investigated.

Keywords: Diamond-like carbon, Raman, Chemical structure, Mechanical property, Friction coefficient