Growth kinetics of TiO2 films deposited by aerosol-assisted chemical-vapor deposition from two different precursors (Ti-n-butoxide and Ti diisopropoxide)

When titanium dioxide films are deposited by delivering a liquid aerosol of titanium-n-butoxide or titanium diisopropoxide, the crystalline and morphological features indicate that the deposition takes place through an aerosol-assisted chemical-vapor deposition (AA-CVD) process. However, the crystalline state depends on the precursor. The evidence of AA-CVD is strongly supported by the quantitative study of the growth rate rg as a function of deposition temperature. The fitting of the experimental rg curves to the equation ∼T3∕2exp(−EA∕RT) indicates that film formation is limited by the gas diffusion + surface reaction of the precursors. The characteristic activation energy EA of such surface reaction depends on the Ti precursor; EA≅112.0kJ∕mol for Ti-n-butoxide and EA≅21.4kJ∕mol for Ti-diisopropoxide.