MOLECULAR-BEAM EPITAXY OF SRTIO3 FILMS ON SI(100)-2X1 WITH SRO BUFFERLAYER

Molecular beam epitaxy of SrTiO3 thin films on a Si(100)-2 x 1 surface has been studied using reflection high-energy electron diffraction (R HEED), an atomic force microscope (AFM) and X-ray diffraction (XRD) as a function of the thickness of the SrO buffer layer and growth temper ature. Epitaxial SrTiO3 films do not grow directly on Si(100). Therefo re, a SrO buffer layer was applied to grow SrTiO3 on Si(100). It was f ound that the SrO layer with a thickness of 100 Angstrom grown at 300- 400 degrees C in oxygen atmosphere of 5 x 10(-8) Torr was sufficient t o grow epitaxial SrTiO3 on Si(100), Then SrTiO3 thin films with a thic kness of 2000 Angstrom were grown on the SrO(100 Angstrom)/Si surface at 400 - 700 degrees C using codeposition of strontium and titanium in oxygen atmosphere of 8 x 10(-8) Torr. At 500 degrees C, the best-qual ity SrTiO3(100) film grew parallel to Si(100), and numerous rectangula r platelike crystals were observed on the surface in the AFM image. Th e crystallinity of the STO films was improved with increasing thicknes s of the SrO layer. The epitaxial relation between SrTiO3 and SrO/Si(1 00)-2 x 1 is also discussed using the RHEED patterns which show streak s and spots.