Structural characterizations of magnetron sputtered nanocrystalline TiN thin films

Nanocrystalline TiN thin films were deposited on Si(111) substrates by DC-magnetron sputtering. The effect of deposition temperature and time on the microstructural morphologies of the thin films was characterized by using FE-SEM and AFM. The texture of the TiN films was characterized by XRD. The films deposited under an Ar + N2 atmosphere initially exhibited a (200) preferred orientation, which subsequently changed to a mixed (111)–(200) orientation with increasing deposition time at 500 °C. The films deposited under a pure N2 atmosphere showed an initial (111) preferred orientation which was then transformed into a mixed (200)–(111) orientation with increasing deposition time. The changes in texture in the TiN thin films are due to one or a combination of factors such as strain energy, surface free energy, surface diffusivity and adatom mobility; the influence of each factor depends on the processing conditions. The grain size of TiN films was measured by XRD. A pyramidal shape and a columnar grain morphology were observed for TiN thin films deposited in Ar + N2 (70:30) and pure N2 atmosphere, respectively, as seen from the FE-SEM analysis. The average surface roughness was calculated from AFM images of the thin films; these results indicated that the average surface roughness was less for the films deposited in pure N2 than for the films deposited in a mixed Ar + N2 atmosphere.