IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Thursday Sessions
       Session SS2-ThM

Paper SS2-ThM2
Fermi Surface Evolution of Ag(111) Films Grown onto Si(111) Surfaces

Thursday, November 1, 2001, 8:40 am, Room 122

Session: Electronic Structure II
Presenter: M.C. Asensio, LURE and ICMM, France
Authors: V. Perez-Dieste, LURE, France
J.F. Sanchez-Royo, LURE and ICMUV, France
J. Avila, LURE and ICMM, France
M. Izquierdo, LURE, France
L. Roca, LURE, France
A. Tejeda, LURE, France
M.C. Asensio, LURE and ICMM, France
Correspondent: Click to Email
Growth of metal films on semiconductor substrates has been the subject of extensive experimental and theoretical studies over the last decades. The determination of the metallization onset at the semiconductor interfaces and the obtention of thin single-crystal metal films, only a few atomic layers thick with atomically flat surfaces, are important goals because of their consequences on the manufacture of integrated circuits and nanosized devices. In this work, we investigate the epitaxial growth of silver overlayers on reconstructed Si(111) surfaces studied by LEED and Photoelectron Diffraction (PhD). The electronic properties of these films have been investigated by high energy resolution Angle-Resolved Photoemission (ARPES) with a synchrotron radiation source. Particular attention has been paid to the determination, by ARPES, of the spectral weight at the Fermi level along large extensions of the reciprocal space of the investigated films, from which the Fermi surface (FS) can be extracted. The evolution of the FS and the valence-band structure as a function of the silver coverage could be measured at several metal coverages. In the submonolayer regime, very localized interface-derived spectral features dominate the density of states at the Fermi level, whereas in the intermediate regime, a complex mixture of states from both the interface and the metallic silver film defines the incipient FS contours. A well defined bulk-like silver FS could be identified already at interfaces of a few Ag monolayers. However, the symmetry of these bulk-like FS contours showed sixfold symmetry rather than the threefold symmetry, characteristic of a Ag(111) single crystal. By PhD, it has been demonstrated that is due to the existence of two domains rotated 60º silver metallic overlayers.