Tribological and Electrical Properties of Chromium Doped Diamond-Like Carbon Films Deposited by Unbalanced Magnetron Sputtering

Chromium-doped diamond-like carbon (DLC:Cr) films were fabricated by using unbalanced magnetron sputtering (UBMS) with chromium (Cr) and graphite (C) targets. We conducted experiments to investigate the tribological, structural, and electrical properties of the DLC:Cr films fabricated with various negative DC bias voltages. The surface of all the DLC:Cr films was smooth and uniform, and the cross-section showed a more compact and clear columnar structure as the negative DC bias voltage increased. The rms surface roughness decreased and the contact angle on the film surface increased with the increase of negative DC bias voltage. Also, the hardness and elastic modulus of the DLC:Cr films showed improvements while the resistivity decreased with the increase of negative DC bias voltage. These results are associated with the ion bombardment and resputtering owing to the effects of the applied negative DC bias voltage.