Structural characterization of TiO<inf>2</inf> thin films prepared by pulsed laser deposition on GaAs(1 0 0) substrates

Abstract

TiO 2 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 O 2 , by pulsed laser deposition (PLD). The effects of both the oxygen pressure and the substrate temperature on the properties of TiO 2 films were investigated. TiO 2 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 TiO 2 films. At 5 Pa of oxygen ambient pressure, rutile TiO 2 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 TiO 2 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. © 2001 Elsevier Science B.V.