Enhanced B diffusion was habitually observed during the growth of ion-bombarded epitaxial layers via molecular beam epitaxy. Ion-bombardment methods were usually required in order to obtain high levels of n-type doping, and the damage caused by low-level ion bombardment was responsible for the enhanced B diffusion. The concentration profiles of as-grown and post-growth annealed samples revealed that the diffusion was a transient effect which occurred at growth temperatures of 600 to 700C. Simulation of the diffusion process demonstrated that almost all of the B participated in diffusion, and that the built-in electric field at the p-n junction led to a further smearing of the B profile.

P.R.Pukite, S.S.Iyer, G.J.Scilla: Applied Physics Letters, 1989, 54[10], 916-8