Structural characterization of TiO2 thin films prepared by pulsed laser deposition on GaAs(100) substrates

Abstract TiO2 thin films on GaAs(1 0 0) substrates were prepared at temperature ranging 30–750°C and pressure from 5×10 −4 Pa base vacuum to 15 Pa O2, by pulsed laser deposition (PLD). The effects of both the oxygen pressure and the substrate temperature on the properties of TiO2 films were investigated. TiO2 thin films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). Optimum parameters have been identified for the growth of high-quality TiO2 films. At 5 Pa of oxygen ambient pressure, rutile TiO2 films with high [1 1 0] orientation were formed at substrate temperature of 700°C. At room temperature (30°C) and 5×10 −4 Pa base vacuum, rutile TiO2 films with a preferred [1 1 0] orientation were also obtained on GaAs(1 0 0) substrates by PLD. Surface morphology of the films showed marked dependence on the substrate temperature. The grain size and their surface roughness increased with raising substrate temperature.