Effect of deposition parameters on composition, structures, density and topography of CrN films deposited by r.f. magnetron sputtering

CrN thin films were fabricated on single crystal silicon substrates by using the reactive radio frequency magnetron sputtering. The effects of deposition parameters on the deposition rate, composition, microstructures, density, and surface roughness of the CrN films have been investigated by AES, XRD, XRR, and AFM. It is found that the cubic-CrN phase can be observed in films with a relatively wide range of nitrogen gas flows. The composition of CrN films was controlled by the gas flows of N2 and the gas flow ratio (Ar/N2). The density of CrN films decreases with the increase of gas flows at room temperature. It is considered that the observed density decrease of CrN films is due to an increasing number of collision between CrN particles with the increasing gas flows of Ar and N2. It is beneficial to produce dense films at high temperature of substrate. The effects of gas flows on the deposition rate showed that the deposition rate decreases with the increase of nitrogen gas flows. The surface roughness of the films increases with the increase of Ar and N2 gas flows, and Ar gas flows play a main role in the surface roughening. It is suggested that the ion and particles bombardment at low gas pressures cause a smoother surface.