ABSTRACT
The shape evolution of Ge dome clusters on Si (001) during Si overgrowth was investigated by HRTEM and EFTEM. Ge moves from the apex to the side facets, where it alloys with the cap silicon forming shallower contact angles. Within 5 monolayers Si-deposition the clusters lose about half of their height, a (001) top facet and {105} side facets form. While coherent domes appear to be uniformly alloyed at Si-coverages of as few as 4 monolayers, dislocated domes still have a Ge-rich core after a 5 monolayer cap.
