Moriarty, P;Ma, YR;Dunn, AW;Beton, PH;Henini, M;McGinley, C;McLoughlin, E;Cafolla, AA;Hughes, G;Downes, S;Teehan, D;Murphy, B

1997

June

Physical Review B

Absence of long-range ordered reconstruction on the GaAs(311)A surface

Published

25 ()

SCANNING-TUNNELING-MICROSCOPY GAAS GAAS(100) GROWTH

55

15397

15400

We have investigated the decapped GaAs(311)A surface using both scanning tunneling microscopy and synchrotron-radiation photoemission. While our data are in broad agreement with the structural model of GaAs(311)A proposed in a recent study [Wassermeier et al., Phys. Rev. B 51, 14721 (1995)], we find considerable differences in the surface order. In particular, the As dimer rows are unbroken overmuch shorter length scales and are highly kinked. We observe a correspondingly lower degree of anisotropy in the surface roughness than that previously reported. An (8 x 1) reconstruction was not observed. An analysis. of As 3d and Ga 3d core-level photoemission spectra suggests that surface As atoms are in only one bonding configuration while surface Ga adopts two different bonding states. We discuss possible origins for the core-level spectra surface components.

COLLEGE PK

0163-1829