Transient enhanced diffusion and electrical activation, after the non-amorphizing Si implantation of lightly B-doped multi-layers, were found to have 2 distinct time-scales; each of which was related to a different class of interstitial defect. At 700C, ultra-fast transient enhanced diffusion occurred within the first 15s, with a B diffusivity enhancement of more than 2 x 105. Immobile clustered B was present at low concentrations, after the ultra-fast transient, and persisted for between 100 and 1000s. The later phase of transient enhanced diffusion exhibited a near-constant diffusivity enhancement of about 104. This was consistent with interstitial injection that was controlled by dissolving {113} interstitial clusters. The relative contributions of ultra-fast and normal transient enhanced diffusion regimes, to the overall diffusive broadening of the B profile, depended upon the proportion of interstitials that escaped capture by {113} clusters that were growing within the implantation-damaged region during annealing. The present results explained an ultra-fast transient enhanced diffusion which had been observed after medium-dose B implantation. In that case, there were enough B atoms to trap a large proportion of interstitials in Si-B clusters, and the remaining interstitials contributed to transient enhanced diffusion without passing through an intermediate {113} defect stage. The data on ultra-fast transient enhanced diffusion pulses placed lower limits of 2 x 10-10 and 2 x 10-13cm2/s on the diffusivities of the Si interstitial and B interstitial, respectively, at 700C.

N.E.B.Cowern, H.G.A.Huizing, P.A.Stolk, C.C.G.Visser, R.C.M.De Kruif, L.K.Kyllesbech, V.Privitera, L.K.Nanver, W.Crans: Nuclear Instruments and Methods in Physics Research B, 1996, 120[1-4], 14-8