An investigation by spot profile analysis low energy electron diffraction of Si grown on GaAs(001)

We present the first in-situ spot profile analysis low energy electron diffraction (SPA-LEED) study of the MBE growth of sub-monolayer coverages (0 to 1 ML) of Si on GaAs(001). Changes in the surface reconstructions from c(4 × 4) via mixed c(4 × 4)/(1 × 2), (1 × 2)/(2 × 1), (1 × 2)/asymmetric (3 × 1) and asymmetric (3 × 1) to a (3 × 1) increasing Si coverage have been monitored. Results are subsequently compared with recent in-situ reflection high energy electron diffraction (RHEED) and scanning tunnelling microscopy (STM) measurements. The continuous splitting between the {1}/{3}- and{2}/{3}- order diffraction spots up to the completion of the symmetric (3 × 1) reconstruction has been examin detail. Domain sizes for each reconstruction have been quantified from the spot profiles.