Ge chemisorption and alloying on the Si(111)-(7×7) surface

Photoemission spectroscopy using synchrotron radiation and reflection high-energy electron diffraction have been used to examine sublayer and multilayer deposits of Ge onto Si(111)-(7×7) substrates. The decomposed Si 2p and Ge 3d core levels as well as angle-integrated valence-band spectra are analyzed as functions of Ge coverage and annealing temperature. The results reveal details concerning the ordering of the surface atoms and the incorporation of Ge into the surface reconstruction. The modification of the surface atomic structure and local chemical composition is correlated with the observed changes in the surface electronic structure.