Arsenic interlayers at the SnrInP 001/interface

The reconstructed InP 001.- 2=4. surface and the arsenic-modified InP 001.- 1=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 SnrInP 001.- 2=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 on 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. q1999 Published by Elsevier Science B.V. All rights reserved