Structural Analysis and Electronic Properties of in on Si(100) from Synchrotron Photoemission Studies

ABSTRACTHigh-resolution photoemission spectroscopy was used to study the initial growth and interaction of In on Si(100). A quantification of the number of Si surface atoms selectively modified in the presence of an In adatom is enabled by decomposing the Si 2p core level into bulk and surface-shifted components; this analysis leads to an In-Si bonding coordination number determination. The In-to-Si bonding coordination number is 3 for very low In coverages and decreases to 2 for one half monolayer coverage. An analysis of the In 4d core levels indicates that the In adatoms occupy equivalent sites for the first 0.5 monolayers. Surface state emission near the top of the valence band persists for coverages exhibiting no Si 2p surface core level shift; implications regarding the different mechanisms I ehind the surface state and surface core level shift are addressed. The results are consistent with a structural model deduced from electron diffraction, Auger, and scanning electron microscopy studies.