Thermodynamic analysis of growth of iron oxide films by MOCVD using tris(e?‘?-butyl-3-oxo-butanoato)iron(III) as precursor

摘要

Thermodynamic calculations, using the criterion of minimization of total Gibbs free energy of the system, have been carried out for the metalorganic chemical vapour deposition (MOCVD) process involving the e???-ketoesterate complex of iron [tris(e?‘?-butyl-3-oxo-butanoato)iron(III) or Fe(tbob)₃] and molecular oxygen. The calculations predict, under different CVD conditions such as temperature and pressure, the deposition of carbon-free pure Fe₃O₄, mixtures of different proportions of Fe₃O₄ and Fe₂O₃, and pure Fe₂O₃. The regimes of these thermodynamic CVD parameters required for the deposition of these pure and mixed phases have been depicted in a `CVD phase stability diagrama€?. In attempts at verification of the thermodynamic calculations, it has been found by XRD and SEM analysis that, under different conditions, MOCVD results in the deposition of films comprising pure and mixed phases of iron oxide, with no carbonaceous impurities. This is consistent with the calculations.