Novel SiGe Coherent Island Coarsening: Ostwald Ripening, Elastic Interactions, and Coalescence;Applied Physics Letters

摘要

Island molecular beam epitaxy (MBE), where elastic repulsion between neighboring islands drives island volume increases with time, while the number of islands per unit area simultaneously diffision currents between islands; (2) dynamic coalescence, where islands themselves find that coarsening kinetics in dense arrays of hut clusters are much different than would deposition flux. The novel kinetics observed here are attributed both to the effects of elastic type of island shape is present in these experiments, in contrast to previous studies (1 3-15). SiOgGeO,z films were grown on Si (001) by MBE details may be found in (16) at 755oC and 0.1 deposition rate. Under these conditions, an extended regime of film thickness exists, born 60 - 130; mass equivalent thickness, in which (501)-faceted pyramidal islands are the only island morphology present. Figure 1 shows an example of a annealing, the island array has coarsened fixture, and all islands are compact (501)- faceted In order to obtain the ensemble coarsening kinetics, the island array was characterized in by annealing at the deposition temperature. The island array clearly coarsens during deposition, since -W(t) increases while decreases but the islands retain their deposition, but drops with annealing. The coarsening kinetics exhibit several unusual First, for coarsening during deposition, increases the rate of coarsening during annealing is much slower than the coarsening during These observations are inconsistent with elementary considerations of capillarity-driven Ostwald ripening and deposition. For deposition at constant rate, 'with no ripening, V(t); In equation (2), V(t) is the deposition rate, f(V,t) is the distribution of island volumes, and V is given by eq. (l). Finally, the evolution of f(V,t) is obtained from the flux continuity during deposition, the increasing areal coverage of islands will continuously increase the elastic interaction energy of the island array. In essence, deposition combined with elastic coarsening. The elastic interaction energy can be captured in the mean field approach coarsening is deposition-dominated in the ripening kinetics for the same deposition rate but with no elastic interactions is also Elastic repulsion between islands in very close proximity to one another may promote deposition, and because the islands are constrained on all sides by other islands, post-deposition annealing, coalescence is far less frequent, and islands tend towards The kinetics of coarsening due to liquid-like coalescence during deposition with no I the island coarsening kinetics we observed during deposition. Pinto et al. have invoked the ripening is enhanced by elastic repulsion energy between the islands, coupled with deposition that forces the islands closer together, thereby continuously driving up the symbols are for continuous deposition.