We successfully demonstrated epitaxial growth of semiconductor (BaSi2)/metal(COSO Schottky-barrier structures on Si(111), for the first time, by molecular beam epitaxy (MBE). The interface between the COSi2 and BaSi2 layers was found to be sharp from transmission electron microscopy (TEM) observations. The current-voltage characteristics measured at room temperature showed clear rectifying properties. When positive bias was applied to the COSi2 layer with respect to the BaSi2 layer, the current increased exponentially. Electron diffraction patterns obtained using reflection high-energy electron diffraction (RHEED) and TEM are discussed. (c) 2008 Elsevier B.V. All rights reserved.