The effect of deposition conditions on the properties of TiN thin films prepared by filtered cathodic vacuum-arc technique

Thin TiN films were deposited at ambient temperature on silicon substrates using the filtered cathodic vacuum-arc technique. The nitrogen flow rate, deposition rate and substrate bias were varied systematically to investigate their effect on the mechanical and structural properties of the films. It was found that an increase in the nitrogen flow rate results in an increased hardness, surface roughness and grain size. The increased ion bombardment due to the higher amount of nitrogen ions makes film nucleation favourable on the denser (111) orientation. An increase in deposition rate results in an increase of stress, hardness and surface roughness. This is due to the increase in the momentum transfer resulting in film densification. Increasing the negative substrate bias decreases both the film stress and the hardness, which can be attributed to ion-induced stress-relief behaviour at higher momentum-energy transfer. The results demonstrate the dominant influence of ion-energy flux on the properties of the films.