Characteristics of TiOx films prepared by chemical vapor deposition using tetrakis-dimethyl-amido-titanium and water

Tetrakis(dimethylamido) titanium (TDMAT) was evaluated as a possible precursor for TiO2 ALD for the first time using H2O as a counter-reactant. Film growth rate, surface morphology, crystallinity, and film composition on the deposition temperature were studied at substrate temperatures of 90–210 °C. Except with the ALD regime, 120–150 °C, the film growth rate decreased linearly with growth temperature below 120 °C and above 150 °C. All films prepared in this study were in the amorphous and the films were highly pure. After annealing the as-deposited films at temperatures of 300–800 °C, change of crystallinity and photocatalytic effectiveness of the TiO2 were investigated. The crystal structure of the films was changed to anatase at annealing temperature above 300 °C and rutile phase was observed with a sample annealed at 500 °C. After annealing at 800 °C, only rutile phase of TiO2 was observed. The crystalline films annealed were shown to have photocatalytic activity in decomposing methylene blue in aqueous solution.