Initial stages of Sb-2 deposition on InAs(001)

We have used in situ scanning tunneling microscopy to study various prepara tion techniques for creating InSb bonds on InAs surfaces by molecular beam epitaxy. When an InAs(001)-(2 x 4) surface is exposed to an Sb-2 flux, the surface changes to an InSb-(1 x 3)-like reconstruction, where one monolayer -deep vacancy islands emerge on the surface due to the change in the compos ition of the reconstruction. The vacancy islands cannot be annealed out usi ng growth interrupts under Sb-2. Extended annealing eventually leads to fur ther surface roughening and a change into a reconstruction that may be even more Sb-rich. As the reconstruction changes from the original (2 x 4) to ( 1 x 3)-like, we do not observe any evidence that the vacancy islands form d ue to material detachment and mass transport from steps. Instead, we iind t hat the vacancy islands develop uniformly across the surface as Sb becomes incorporated into the reconstruction. (C) 2001 Elsevier Science B.V. All ri ghts reserved.