Effects of Bias Voltage and Substrate Temperature on the Mechanical Properties and Oxidation Behavior of CrWSiN Films

CrWSiN films were prepared through the co-sputtering technique, and the process variables were substrate bias voltage and temperature. The mechanical properties of hardness and elastic modulus of the CrWSiN films were dominantly affected by their average crystallite size and by substrate bias voltage and temperature. Moreover, the effect of substrate temperature was more evident than that of substrate bias. The highest hardness and elastic modulus of 42.6 and 459 GPa, respectively, were obtained for the Cr20W28Si9N43 film fabricated at a substrate temperature of 400 degrees C, which exhibits an evident advantage over the 25.0 and 323 GPa values for the Cr21W28Si9N42 film fabricated at room temperature. In contrast, an increase in negative bias voltage to -100 V on the substrate decreased the mechanical properties compared to one prepared using a similar process without applying the negative bias voltage. The oxidation resistance of the Cr-enriched Cr37W4Si10N49 and Cr37W5Si10N48 films was superior to that of the Cr20W28Si9N43 films with near-equal Cr and W contents annealed at 900 degrees C in air. The formation of a surficial Cr2O3 layer plays a vital role in restricting subsequent oxidation for CrWSiN films.