[WeB2] Thin Film Growth of Oxides

11:00 AM - 11:15 AM JST(2:00 AM - 2:15 AM UTC)

[WeB2-03] Effect of Deposition Temperature on the Composition of Al_1-xTi_xO_y Films via Single-Source Mist-CVD System

〇Thin Nu Soe¹, Hiroshi Otake¹, Yusui Nakamura¹, Zenji Yatabe² (1. Kumamoto Univ. (Japan), 2. Hokkaido Univ. (Japan))

The influence of deposition temperature on the composition of mist-CVD deposited aluminum titanium oxide (Al_1-xTi_xO_y) thin films was investigated. We studied the relationship among substrate temperature, deposition rate, and film stoichiometry by analysing the growth mechanisms of Al₂O₃ and TiO₂ thin films. The film deposition was performed on 2-inch p-Si substrate at different substrate temperatures, in a range of 250°C to 450°C with an increment of 50°C. Congruent stoichiometric transfer from the precursor solution to the film is achieved at 400°C and 450°C, where the deposition rates are almost the same. At temperatures below 400°C, more Ti were incorporated in the films due to lower deposition rate of Al₂O₃ than that of TiO₂. These results show that the deposition temperature strongly affects the composition of Al_1-xTi_xO_y films in single-source mist-CVD system. In addition, the obtained films exhibited smooth surfaces with tuneable refractive index and optical bandgap, which are all comparable with those reported for high-quality amorphous Al₂O₃ and anatase TiO₂ films deposited by ALD.