Metalorganic chemical vapor deposition of Cu films from bis(t-butyl-3-oxo-butanoato)copper(II): thermodynamic investigation and experimental verification

For the metalorganic chemical vapor deposition (MOCVD) of copper films using the β-diketonate complex copper t-butylacetoacetate or bis(t-butyl-3-oxo-butanoato)copper(II) as the precursor material, the equilibrium concentrations of various condensed and gaseous phases have been thermodynamically calculated, using the criterion of minimization of total Gibbs free energy of the system. The study predicts the deposition of films of metallic copper without the presence of any oxides, even in an inert atmosphere of argon. The Cu films so formed would contain a small amount of carbon, which reduces to zero at higher temperatures. In the reactive ambient of hydrogen, carbon-free copper film is predicted over a wide range of substrate temperatures and total reactor pressures. The thermodynamic yield shows reasonable agreement with experimental observations, though the removal of carbon from the MOCVD-grown copper films in hydrogen is not as complete as the thermodynamic calculations predict.