The atomic structures of the Si(111)-√3×√3- and -6×6-Au surfaces studied by low-energy ion scattering

Abstract

Two Au-induced Si(111) reconstructions, the (3)1/2×(3)1/2 and 6×6, were studied using impact-collision ion scattering spectroscopy with a 5-keV Li+ ion beam. The nearly identical ion scattering results for the two surfaces reveal that the local atomic structures of the (3)1/2×(3)1/2 and 6×6 reconstructions are closely related. The scattered-ion angular distributions clearly show that the Au atoms are not embedded in the Si surface. A comparison of the experimental data with computer simulations gives excellent agreement for a model in which both surfaces are composed of a mixture of the honeycomb and centered hexagon structures proposed previously for these surfaces, although such a determination is not unique.