Growth kinetics of TiO_2 films deposited by aerosol-assisted chemical-vapor deposition from two different precursors (Ti-n-butoxide and Ti diisopropoxide)

摘要

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 r_g as a function of deposition temperature. The fitting of the experimental r_g curves to the equation ～T~(3/2) exp(-E_A/RT) indicates that film formation is limited by the gas diffusion + surface reaction of the precursors. The characteristic activation energy E_A of such surface reaction depends on the Ti precursor; E_a ≈ 112.0 kJ/mol for Ti-n-butoxide and E_A ≈ 21.4 kJ/mol for Ti-diisopropoxide.