Two-dimensional growth and structural characterization of oxide ceramic thin films grown by laser molecular beam epitaxy

Atomically regulated unit-cell by unit-cell homoepitaxial SrTiO3 (STO) and heteroepitaxial BaTiO3 (BTO) films were fabricated on STO (100) substrates by laser molecular beam epitaxy. The fine streak patterns and more than 1000 cycles undamping intensity oscillation were obtained by in situ reflection high-energy electron diffraction (RHEED). The films were examined by atomic force microscopy (AFM), X-ray diffraction (XRD), x-ray photoelectron spectrometer (XPS), (phi) scan, and the cross-section high-resolution TEM. The root-mean-square surface roughness of the films is about 0.1 nm. The FWHM of the XRD (omega) -rocking curve for the (200) diffraction peak of BTO film is 0.235 degrees. The results indicate that the films have a high degree of c-oriented epitaxial crystalline structure and the surfaces of films are atomically smooth.