Initial stages of Sb2 deposition on InAs(0 0 1)

We have used in situ scanning tunneling microscopy to study various preparation techniques for creating InSb bonds on InAs surfaces by molecular beam epitaxy. When an InAs(0 0 1)-(2×4) surface is exposed to an Sb2 flux, the surface changes to an InSb-(1×3)-like reconstruction, where one monolayer-deep vacancy islands emerge on the surface due to the change in the composition of the reconstruction. The vacancy islands cannot be annealed out using growth interrupts under Sb2. Extended annealing eventually leads to further surface roughening and a change into a reconstruction that may be even more Sb-rich. As the reconstruction changes from the original (2×4) to (1×3)-like, we do not observe any evidence that the vacancy islands form due to material detachment and mass transport from steps. Instead, we find that the vacancy islands develop uniformly across the surface as Sb becomes incorporated into the reconstruction.