Studies On Preparation And Characteristics Of Metal/Chromium Nitride Films Deposited By Radio Freqency Magnetron Sputtering

Using radio frequency (RF) magnetron sputtering method, CrN thin films with good crystallinity were successfully deposited on Si (100), ITO glass substrates and Cr, Ti metal buffer layer, respectively, by manipulating deposition parameters including the sputtering power, N2 gas flow percentage, substrate bias and sputtering pressure(They are express as CrN(Si), CrN(ITO), Cr/CrN and Ti/CrN, respectivly). The optimal deposition parameters of the CrN film with (111) preferred orientation were obtained by X-ray diffraction (XRD), and there was no diffraction peak relating to Cr, Cr2N, Ti or TiN. The variations of deposition parameters obviously influenced the film crystallization quality and the residual compressive stress, thereby affected the lattice constant and the grain size of CrN films. The average grain sizes of the optimal CrN (Si), CrN (ITO), Cr/CrN and Ti/CrN samples were 21.72,21.52,39.15 and 19.08 nm, respectively.Scanning electron microscope (SEM) analyses showed that the surface structure of CrN (Si), CrN (ITO), Cr/CrN and Ti/CrN thin films were all compact, and the grain had a bract-like structure, while the others had the typical tetrahedral pyramid structure. And after high-heat treatment, among all the films above, the surface were damaged seriously, especially for the Cr/CrN film. Energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) analyses showed that after high-temperature annealing, the main chemical composition transforms from CrN to Cr2N, the related information of Cr was disappeared, and the content of oxides did not change significantly, which showed that the films still have good oxidation resistance under a high-temperature of 800 ℃.And the resistivities of these films were 2.75,1.58,0.18 and 0.78 Ω.cm, respectively, which were in proportion to the crystallization of the films. With the change of deposition parameters, especially the sputtering power and sputtering pressure, the resistivity of CrN (Si) thin films changed exponentially, while the resistivity of CrN (ITO), Cr/CrN and Ti/CrN films multiplied.With the change of deposition parameters, the reflectivity variations of CrN (Si) films were in accordance with the growth of CrN (111) preferred orientation. The maximum reflectivity of 31.1% of CrN (Si) thin films occurs at a wavelength of 1130 nm in the near infrared region. However, as the deposition parameters changed, the reflectivity of CrN (ITO) films were inversely proportional to its crystallization quality. And at a wavelength of 895 nm, the maximum reflectivity of 25.5% of the optimal CrN (ITO) thin film occurs.