Heteroepitaxy of SrTiO3 on vicinal Si(001): Growth and kinetic effects

Heteroepitaxy of SrTiO3 on vicinal Si(001) substrates was accomplished using molecular beam epitaxy by codepositing Sr and Ti at a low-temperature-and-low-oxygen-pressure condition at the early stage of film growth. X-ray photoelectron spectroscopy and reflection-high-energy-electron diffraction showed that the SrTiO3 films grown by this method exhibited better chemical and structural behaviors than those produced by layer-by-layer deposition under similar conditions. Scanning tunneling microscopy revealed that a well-defined step-terrace morphology was retained on the SrTiO3 film grown by codeposition on a vicinal Si(001) substrate. These results suggest that kinetic effects play an important role and the presence of Sr promotes titanium oxidation by providing a different transition state with a lower Ti oxidation barrier.