Arsenic interlayers at the Sn/InP(001) interface

The reconstructed InP(001)-(2 X 4) surface and the arsenic-modified InP(001)-(1 x 1)-As surface were included in a comparative study in order to investigate the influence of arsenic interlayers on the interface formation;Interface reactions and the morphology of tin films on InP(001) have been investigated using core level photoelectron spectroscopy (SXPS) and LEED. A strong reaction between InP and the deposited tin is observed on the Sn/InP(001)-(2 x 4) interface. An arsenic interlayer passivates the substrate against this reaction. Arsenic gives rise to layer-by-layer growth mode up to Sn layer thicknesses of 1 nm of Sn an InP(001), while without this interlayer only one flat monolayer of Sn was formed. Beyond these limits three-dimensional metallic tin islands grow on both surfaces. Annealing of the tin films to 650 K after the last coverage initiates coagulation of the tin and lifts the passivating effect of the arsenic interlayer. (C) 1999 Published by Elsevier Science B.V. All rights reserved.