The relationship between so-called anomalous dopant diffusion and end-of-range defects was considered. It was noted that a knowledge of the type and origin of such defects permitted an understanding of how they affected dopant diffusion. Dislocation loops tended to behave like gettering centers, because of the partial dislocations at their periphery and the associated strain fields. On the other hand, they nucleated and grew in size during annealing and reduced their density via the emission and capture of the Si self-interstitial atoms of which they were composed. Thus Ostwald ripening theory, when applied to the growth of extrinsic loops, was very useful in understanding and simulating diffusivity enhancement in the loop region. Above all, it made it possible to describe the phenomenon as being due to interactions between the dopant and a population of extrinsic defects. The evolution of the size and density of these defects permitted the evolution of the Si self-interstitial supersaturation surrounding them to be deduced. The initial supersaturation before nucleation was at least 5 orders of magnitude higher than the equilibrium value, and dramatically decreased during the first second of annealing. This exponential decay with time was the cause of the transient enhancement of B diffusivity; via the interstitial component of B diffusion. It was concluded that this reasoning was applicable not only to end-of-range defects, but could be extended to other extrinsic defects and dopants; such as the {113} defects which were found after annealing B that was directly implanted into crystalline Si.

A.Claverie, C.Bonafos, A.Martinez, D.Alquier: Solid State Phenomena, 1996, 47-48, 195-204