Preparation of CrN thick films by high-rate middle-frequency unbalanced magnetron sputtering

A middle-frequency (MF) unbalanced magnetron sputtering system equipped with an electron source was designed and used for deposition of CrN thick films under various MF power (1.4–14 kW) at fixed temperature, pressure, and gas flow rate. The deposition rate was increased with increasing MF power and the structure and N/Cr ratio of the deposited CrN films exhibited a complicated behavior, where the CrN films were a polycrystalline structure and the films deposited under optimized conditions exhibited a dense columnar structure and a micro-hardness of 16 GPa. The dependence of the structure and micro-hardness on MF power was interpreted by the power deposition efficiency.