Diffusion of ion implanted boron in high Ge content SiGe alloys

Boron diffusion in high Ge content SiGe alloys (with Ge content > 50%) is studied using ion-implantation and Secondary Ion Mass Spectroscopy. The samples were grown using Low Energy Plasma Enhance Chemical Vapor Deposition and furnace annealing was carried out in evacuated ampoules. We observe an increase in boron diffusivity with Ge content as we go from 50% Ge in SiGe alloy to pure Ge. However, the increase in diffusivity is not substantial. The results suggest the likelihood of an interstitial mediated diffusion mechanism for B in SiGe over the whole alloy range.