The effects of DC power on the physical properties and surface topography of sputtered TiN nanostructured thin films

Four high quality nanostructured thin films of titanium nitride, with thicknesses equal to 81, 325, 485 and 565 nm respectively, were deposited on glass substrates by the reactive magnetron sputtering method using different DC power values (from 200 to 410 W). The results revealed that the DC power plays a crucial role in the evolution of the thickness, topography, microstructure, optical and semiconducting properties of the resulting thin films. Specifically, an increase in the DC power enhances the crystalline order of the samples, consequently; the energy band gap values and the electrical resistivity decrease. Also, a competitive growth of crystalline planes of different orientations was found as a consequence of the increment of the grain size. In addition, the influence of DC power on the 3-D surface morphology of these thin films was investigated. The largest peak height and also the largest valley depth from the mean surface increased at higher amounts of DC power. The flexible variation of the physical properties of thin films with the simple and reproducible variation of the DC power in the sputtering process could be exploited in the use of these samples in specific technological applications.