Control of thin film structure by reactant pressure in atomic layer deposition of TiO2

Atomic layer growth of TiO2 films from TiCl4 and H2O was examined. It was established that polycrystalline films of pure rutile, pure TiO2-II, or a mixture of them could be obtained at the same growth temperature (400 degrees C) and at the same TiCl4 vapor pressure (0.34 Pa) applying different water vapor pressures during the water pulse. Possible growth mechanisms leading to formation of different structures are discussed.