In situ reflection high energy electron diffraction was used to study the surface micromorphology of SixSnyGe1 - (x) (-) (y) / Si(100) heterostructures obtained by molecular beam epitaxy. The obtained reflection high energy electron diffraction data allowed us to conclude that the epitaxial SixSnyGe1 - x - y films are grown by the Stranski-Krastanov mechanism. It was established that SixSnyGe1 - x - y and Ge1 - zSnz wetting layer thicknesses depend on the substrate temperature. The observed surface superstructures changed during the wetting layer growth. (c) 2013 Elsevier B.V. All rights reserved.