Low-Energy Electron-Diffraction Study of the Cleaved (110) Surfaces of InSb, InAs, GaAs, and GaSb

Abstract

The (110) surfaces of InSb, InAs, GaSb, and GaAs produced by the Gobeli‐Allen cleavage technique, have been studied by low‐energy electron diffraction. The unit mesh at this surface of these III‐V compounds has the same dimensions as the substrate unit mesh. A strong asymmetry in the intensity of the hk and hk̄ diffraction beams reveals that the surface atoms preferentially shield the atoms in the second layer and that the arrangement of atoms at the surface is not the same as the arrangement of atoms in the bulk of the crystal. No change in the surface structures was observed by heating the crystals close to their melting points following the cleavage. These same structures could also be produced by argon ion bombardment and anneal. The sticking probability for oxygen on the (110) surface was established to be less than 10⁻⁵ for all of the materials investigated.