Effect of temperature and bias voltage on electrical and electrochemical properties of diamond-like carbon films deposited with HiPIMS

The relatively high electrical resistivity of diamond-like carbon (DLC) film is one of the main drawbacks when applied in electronic device. In this study, DLC films were synthesized on 304 stainless steels by high power impulse magnetron sputtering (HiPIMS) process and the effect of deposition temperature and bias voltage on the microstructure, electrical and electrochemical properties, hardness and adhesion strength of the DLC films were investigated. The sp(2)/sp(3) ratio of DLC films first decreased then increased and the surface became denser as bias voltage increasing from 0 to -400 V. While the film turned into graphite-like structure and became incompact when deposition temperature rose from 100 degrees C to 300 degrees C. The interfacial contact resistance (ICR) got reduced by increasing bias voltage and deposition temperature. However, as the deposition temperature increased to 300 degrees C the anticorrosion ability and hardness of DLC films deteriorated. The DLC films deposited at 300 degrees C presented soft and had better adhesion strength than hard DLC films deposited at 100 degrees C. DLC films deposited at -400 V bias and 300 degrees C had the lowest ICR while DLC films deposited at -400 V bias and 100 degrees C had the best performance when ICR, corrosion resistance and hardness were all taken into consideration.