ANTIMONY ADSORPTION ON III-V(110) SURFACES - GROWTH AND STRUCTURE STUDIED BY PHOTOEMISSION AND PHOTOELECTRON DIFFRACTION

The adsorption of antimony on III-V(110) surfaces has been studied as a function of overlayer coverage and annealing temperature using high- resolution soft x-ray photoemission (SXPS). A detailed line shape anal ysis of the Sb4d core level emission revealed that the deposition of 3 -5 monolayers at RT and subsequent annealing up to 620K, leads to Sb4d core level emission being well resolved into two chemically shifted c omponents for Sb on GaAs, GaP, InAs and InP (110) surfaces indicating highly ordered monolayers. The well ordered epitaxial monolayers are i deal candidates for photoelectron diffraction studies. This method pro vides further information on their geometrical structure, since the pr ecise nature of these monolayers is still under discussion. Therefore the overlayer emission lines were monitored as a function of polar ang les and photon energy. The resulting diffraction patterns show strong and significant variations for all systems under study. The experiment al results are compared to calculations within a multiple scattering c luster model for various adsorption geometries of the Sb ML within the ECLS model. Considering the Sb4d core level emission the two chemical ly shifted components, which have distinct diffraction patterns, allow a clear assignment to the two distinct adsorption side's to be made.