We have studied the Schottky barrier formation of Ga/Si(111)‐(2×1), Sb/Si(111)‐(2×1) and Sb/GaAs(110) interfaces via photoemission measurements of the following coverage‐dependent quantities: the Fermi level position at the interface relative to the valence band maximum Ev (i.e., p‐type Schottky barrier ΦBP), work function, Si bulk and surface 2p core level binding energies, Ga 3d and Sb 4d core level energies, and Si surface states. Using a lightly‐doped (∠15 Ω cm) p‐type Si(111)‐(2×1) sample which was cleaved with a single‐domain (2×1) surface structure, we observe large deviations from the ’’1/3 band gap‐rule’’ for p‐type Schottky barriers ΦBP with both Ga and Sb; i.e., ΦBP ? 0.07 eV for Ga/Si(111) and ΦBP ? 0.66 eV for Sb/Si(111). The core level spectra for Ga and Sb for coverages in the 0.3 – 12 Å range show very sharp core levels (observed FWHM ∠0.4–0.5 eV), indicative of a ’’simple’’ interface without complex multiple binding sites or displacive reactions; this is in contrast with our studies of the Sb/GaAs(110) interface, for which the Sb core levels are significantly broadened (∠1 eV FWHM). These studies are discussed in view of current models of Schottky barriers on covalent semiconductors.

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