A study was made of high-concentration B diffusion by using a precipitation model. Recent experimental data on the annealing of B which had been implanted into pre-amorphized Si gave the opportunity to analyze, with the aid of simulations, the precipitation kinetics and the effect of dislocation loops which existed at the amorphous/crystalline interface. A non-equilibrium point defect diffusion model was used which explicitly included equations that described the precipitation kinetics. The initial conditions took account of the high level of activation which was observed after solid-phase epitaxy. This affected both the sheet resistance and the doping profile shape at the end of the process. It was also shown that correct modelling of these diffused profiles included the effect of dislocation loops, at the amorphous/crystalline interface, which acted as sinks for interstitials. It was noted that more classical formulations of the diffusion equation did not require the modelling of such phenomena since an equilibrium concentration of point defects was implicitly assumed.

B.Baccus, E.Vandenbossche, M.Lannoo: Journal of Applied Physics, 1995, 77[11], 5630-41