EPITAXIAL TIO2 AND VO2 FILMS PREPARED BY MOCVD

Titanium and vanadium oxide systems were selected to study the growth of thin epitaxial film in a metal-organic chemical vapor deposition (MOCVD) process. Epitaxial TiO2 and VO2 films were obtained on sapphire (1120BAR), (0001), and (1102BAR) but not on Si(111). Eight distinct substrate-film epitaxial relationships have been determined by X-ray diffraction studies using a four-circle diffractometer. It was found that none of the eight epitaxial systems had a good lattice match between substrate and film. But further investigation revealed that substantial similarity existed in the local atomic patterns of the substrate and the film for all these systems. Nevertheless, it should be emphasized that mismatches of the local atomic patterns for these systems are, in general, substantially larger than those observed in the epitaxial systems containing semiconductor materials such as silicon and GaAs.