The properties of B-doped Si layers obtained by bombardment with BF2+ molecular ions were studied by using Rutherford back-scattering spectrometry, transmission electron microscopy, secondary ion mass spectrometry, and incremental sheet resistance and sheet Hall coefficient measurements involving anodic sectioning. The implantation step was responsible for the formation of interstitial aggregates at the amorphous/crystal interface. The size of these aggregates, and the total number of defects involved, depended upon the implantation conditions. It was different for samples implanted at medium currents or high currents. During high (900 to 1000C) temperature diffusion in an inert atmosphere, the aggregates annealed out and caused interstitial over-saturation. As a result, diffusion enhancement occurred. This was modelled by simulating the creation of an excess of interstitials by heat treatment in a partially oxidizing atmosphere.

G.Queirolo, P.Caprara, L.Meda, C.Guareschi, M.Anderle, G.Ottaviani, A.Armigliato: Journal of the Electrochemical Society, 1987, 134[11], 2905-11