COAXIAL IMPACT COLLISION ION-SCATTERING SPECTROSCOPY STUDIES OF SB ADSORPTION ON THE 2-DOMAIN (100) SURFACE OF SILICON

We present experimental and simulated coaxial impact collision ion sca ttering spectroscopy (CAICISS) data from the clean Si(100) surface and a Si(100)-(2 X 1)-Sb two-domain surface. The (2 X 1)-Sb surface was f ormed, following Sb deposition at 300 degrees C and annealing to 540 d egrees C, and is shown to comprise of rows of symmetric Sb-dimers with an intra-dimer spacing of 2.7 +/- 0.1 Angstrom and a height above the silicon surface of 1.5 +/- 0.2 Angstrom. There is also evidence, from near critical edge scans, for the existence of dimer vacancies and si ngle defects on this surface which give rise to additional coverage de pendent intensity above polar angles > 165 degrees. The coverage depen dence of the defect and dimer vacancy concentrations on the surface ha s been estimated and at Sb coverages > 2.0 monolayers the overlayer ap pears to be amorphous in nature.