Growth of TiO2 thin films on Si(001) and SiO2 by reactive high power impulse magnetron sputtering

Abstract

ABSTRACTThin TiO2 films were grown on Si(001) and SiO2 substrates by reactive dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) at temperatures ranging from 300 to 700 °C. Both dcMS and HiPIMS produce polycrystalline rutile TiO2 grains, embedded in an amorphous matrix, despite no postannealing taking place. HiPIMS results in significantly larger grains, approaching 50% of the film thickness at 700 °C. In addition, the surface roughness of HiPIMS-grown films is below 1 nm rms in the temperature range 300–500 °C which is an order of magnitude lower than that of dcMS-grown films. The results show that smooth, rutile TiO2 films can be obtained by HiPIMS at relatively low growth temperatures, without postannealing.