Kinetic study of the metalorganic chemical vapor deposition of PbTiO3 films from Pb(C2H5)4/Ti(i-OC3H7)4/O2 reaction system

Lead titanate (PbTiO3) films are prepared from mixtures of tetraethyl lead [Pb(C2H5)4], titanium tetraisopropoxide [Ti(i-OC3H7)4] and oxygen at temperatures ranging from 823 to 873 K by the low-pressure chemical vapor deposition (LPCVD) method. The kinetics of the film growth process has been studied, including investigating the growth rate dependency at various substrate temperatures and the concentrations of Pb(C2H5)4, Ti(i-OC3H7)4, and O2, respectively. A reaction model applying the Eley-Rideal mechanism is proposed to explain the experimental film growth rate dependency. The model involves (i) a strong surface adsorption species, Pb(C2H5)4, chemisorbing on the substrate surface to react with a dissociatively adsorbed oxygen to form PbO, (ii) a less adsorptive species, Ti(i-OC3H7)4, directly coming from the gas phase to react with the surface adsorbed species to form PbTiO3 films. The proposed reaction model fits the growth rate data quite well.