Annealing of phosphorus-doped Ge islands on Si(001)

To study the effect of phosphorus on the evolution of Ge islands on Si(001), phosphorus-doped islands were annealed in a H2 ambient and undoped islands were annealed in a PH3/H2 ambient. In both cases phosphorus stabilizes the island structure and reduces coarsening during annealing. The changes of island shape during annealing are consistent with phosphorus influencing the thermodynamic properties of the islands, while the slower decrease in the density of islands when phosphorus is present is consistent with phosphorus kinetically retarding surface diffusion of Ge atoms.