Commercial molecular beam epitaxy production of high quality SrTiO3 on large diameter Si substrates

The authors report on the development of a molecular beam epitaxy production process for the epitaxial growth of high quality, single crystal, single phase SrTiO3 (STO) films on Si substrates with diameter up to 8in. Reflection high-energy electron diffraction indicated that the STO growths proceeded two dimensionally with excellent stoichiometric control, as confirmed by Rutherford backscattering spectroscopy measurement. Excellent crystalline quality has been confirmed by x-ray diffraction rocking curves of the STO (200) reflection with narrow full width at half maximum of 0.06° for a 1200Å thin film. Atomic force microscopy images show smooth, defect-free STO surface with a root-mean-square roughness value as low as ∼0.6Å. Cross-sectional transmission electron microscope images reveal an abrupt interface between STO and Si, with a very thin SiO2 interfacial layer.