Control of morphological transitions during heteroepitaxial island growth by reflection high-energy electron diffraction

In this work we studied the formation of well-faceted features during the growth of Ge and SiC islands on (001)Si representing a lattice mismatch of 4 and 20%, or a Stranski–Krastanov and Vollmer–Weber growth mode, respectively. A method to recognize morphological transitions in situ by reflection high-energy electron diffraction is presented. The analysis of the pattern is based on the appearance of 2D and 3D diffraction features as well as on the shift of the position of transmission spots due to refraction effects on tilted planes. The latter effect will be demonstrated for the formation of Ge-hut clusters on Si with its typical {105} facets as well for the formation of Si pyramids with {11n} facets (n≈5–9) during nucleation of SiC islands.