Abstract:
Size distribution of Ge islands formed in the course of Ge heteroepitaxy on Si(111) was studied by scanning tunneling microscopy in experiments of two types: (i) conventional molecular beam epitaxy (MBE) and (ii) pulsed ($0.5$ s) irradiation with Ge ions of energy $\simeq 200\,$ eV at instants of time corresponding to a filling degree $>0.5$ for each monolayer. Experiments were performed at a temperature of $350^\circ\,$ C. The pulsed ion-beam irradiation during heteroepitaxy leads to a decrease in the average size of Ge islands, an increase in their concentration, and a decrease in the root-mean-square deviation from the mean, as compared to the analogous values in conventional MBE experiments.