The influence of thermal annealing of Sb/GaAs(110) interfaces is studied in situ by high-resolution photoemission spectroscopy. A detailed line shape analysis of the Sb 4d core-level spectra shows that Sb deposition at room temperature (RT) does not lead to perfectly ordered growth of the first monolayer (ML), as previously assumed. Annealing at 330 °C results in a highly ordered overlayer that is desorption limited to 1 monolayer (ML). The degree of order affects the barrier height at the interface drastically: whereas RT deposition produces band bending of up to 0.6 eV on p-GaAs, annealing reduces the position of the surface Fermi level by a factor of 2 to a position 280 meV above the valence-band maximum of the GaAs. This pinning position corresponds to the maximum of the two-dimensional valence-band structure of the ordered-Sb monolayer. Band bending effects attributable to the generation of intrinsic defects in the GaAs during deposition or annealing processes were not observed.
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Schäffler et al. (1987) studied this question.