Surface atomic structure of <i>c</i> (2×2)-Si on Cu(110)

The technological importance of Schottky barriers has led to many experiments of metal-on-semiconductor systems. Here we present an example of the inverse case by depositing a semiconductor on a metal, studying the very early stages of the metal-semiconductor interface formation. We show that 0.5 monolayers of Si on Cu(110) form an ordered <i>c</i> (2×2) overlayer and resolve its geometrical structure. Using full-hemispherical x-ray photoelectron diffraction, we find that Si atoms form an almost coplanar layer, replacing one out of two Cu surface atoms.