THERMODYNAMIC ANALYSIS OF BA-SR-TI OXIDE FILM COMPOSITIONS IN THE PROCESS OF METALLORGANIC CHEMICAL-VAPOR-DEPOSITION

We have calculated the equilibrium composition of the solid phase prod uced in the metallorganic chemical vapor deposition (MOCVD) process th at uses Ba(2,2,6,6-tetramethyl-3,5-heptanedione)(2), Sr(2,2,6,6-tetram ethyl-3,5-heptanedione)(2), Ti(O-i-C3H7)(4), and oxygen as reactants e ither separately or together. The results indicate that barium stronti um titanate (BST) films of good dielectric properties are obtained whe n a proper amount of the Ti source is used in the chemical vapor depos ition (CVD) feed. The Ti source is effective in modifying the Ba and S r fractions in the BST films, but the Ba source is not so effective in modifying the film composition. Oxygen addition to the feed suppresse s graphite deposition but does not affect the metal composition of the film.