Absorption spectroscopy at the Cu-2p edges in Cu/Si(111)7 × 7 interface

We report on a study of the empty states at the Cu/Si(111)7 × 7 interface via polarization-dependent CuL2,3X-ray absorption spectroscopy (XAS) as a function of the Cu coverage (0.25-5 ML). Joint analysis of the CuL3XAS line-shapes of Cu-based reference compounds allows us to interpret the high coverage spectra in terms of pseudo-stoichiometric Cu-silicides.