THE RELATIONSHIP BETWEEN THE MOCVD PARAMETERS AND THE CRYSTALLINITY, EPITAXY, AND DOMAIN-STRUCTURE OF PBTIO3 FILMS

Lead- and titanium-based oxide thin films were prepared by the metal-o rganic chemical vapor deposition technique (MOCVD) and the relationshi p between the film structures and the processing parameters, such as t he ratio of Pb/Ti precursors in the gas phase, substrate materials, su bstrate surface orientation, and growth temperature, was systematicall y studied. It was found that whether a single-phase stoichiometric PbT iO3 film could be obtained depended on both the Pb/Ti precursor ratio in the gas phase and the deposition temperature. Under appropriate con ditions, stoichiometric PbTiO3 films could be obtained on all the subs trates including silicon, MgO, alpha-Al2O3, SrTiO3, and LaAlO3. The Pb TiO3 films grown on silicon substrates were always polycrystalline, wh ereas epitaxial PbTiO3 films were obtainable on all the other substrat es. For epitaxial PbTiO3 films, the epitaxial relationship, crystallin ity, and domain structures were found to be a function of both the sub strate materials and surface orientation as well as the deposition tem perature. X-ray rocking curves (omega scan) of the (100) and (001) pla nes of PbTiO3 epitaxial film and PbTiO3 single crystal revealed the in herent nature of the domain structures in PbTiO3.