GE CHEMISORPTION AND ALLOYING ON THE SI(111)-(7X7) SURFACE

Photoemission spectroscopy using synchrotron radiation and reflection high-energy electron diffraction have been used to examine sublayer an d multilayer deposits of Ge onto Si(111)-(7 X 7) substrates. The decom posed Si 2p and Ge 3d core levels as well as angle-integrated valence- band spectra are analyzed as functions of Ge coverage and annealing te mperature. The results reveal details concerning the ordering of the s urface atoms and the incorporation of Ge into the surface reconstructi on. The modification of the surface atomic structure and local chemica l composition is correlated with the observed changes in the surface e lectronic structure.