Transition in growth mode by competing strain relaxation mechanisms: surfactant mediated epitaxy of SiGe alloys on Si

In: Applied Physics Letters, Jg. 85 (2004) ; Nr. 15, S. 3056 (3p)
ISSN: 1077-3118, 0003-6951
Zeitschriftenaufsatz / Fach: Physik
Fakultät für Physik » Experimentalphysik
Surfactant mediated epitaxy of Si(1−x)Gex alloys on Si(111) can, besides technological importance, clarify the influence of the lattice mismatch during surfactant mediated heteroepitaxial growth. For low Ge concentration we find an immediate layer-by-layer growth, whereas at high Ge concentration a roughening transition followed by relaxation of the lattice mismatch in a periodic dislocation network is preferred. This behavior can be explained by comparing the dislocation nucleation rate on a smooth surface with the island nucleation rate on a pseudomorphic film.