Amorphous aluminum titanate films are prepared on silicon substrates by low-pressure chemical vapor deposition (CVD) using a mixture of aluminum tri-sec-butoxide (ATSB), titanium tetrachloride (TiCl4), CO2, and H-2 as the reactants (the ATSB/TiCl4/CO2/H-2 system). The effects of the CO2/H-2 and ATSB inputs and substrate temperature on the growth, microstructure, and composition of the CVD Al2O3-TiO2 films are discussed. The films have an increased growth rate and an increased Ti content at lower temperatures. The adsorption-controlled reaction is identified, which is attributed to the gas/solid reaction to weaken the film/substrate interface. The growth rates are also higher at higher H-2 and ATSB flows. The film thickness is 0.47-1.13 mum for the CO2/H-2-varying system and of 0.34-1.37 mum for the ATSB-varying system at deposition temperatures of 350-500 degreesC. The proposed reactions are presented to explain the film growth. The determined adsorption energy can explain the effect of temperature on composition. (C) 2004 American Vacuum Society.