Nucleation and evolution of Si1-xGex islands on Si(001)

In this study we report a systematic investigation of the metastable morpho logies of Si1-xGex layers obtained by the interplay of kinetics and thermod ynamics during growth on Si(001). We show that three main growth regimes ca n be distinguished as a function of the misfit and of the deposited thickne ss. They correspond to three equilibrium steady state morphologies that con sist of(105)-facetted hut islands, huts and domes in co-existence, and a bi modal size distribution of domes, respectively. The shape transitions betwe en these states are attributed to different levels of relaxation. (C) 2000 Elsevier Science B.V. All rights reserved.