The capture of a flux of vacancies, by a band of extrinsic dislocation loops, was observed in Sb-doped superlattices. Annealing, in NH3, of superlattices which contained a band of dislocation loops resulted in the injection of vacancies. These enhanced the diffusion of Sb spikes which were located between the surface and the loop band. By deducing the diffusivities in Sb spikes on either side of the loop band, it was concluded that over 90% of the injected vacancies were captured by the loops. Implantation and annealing in Ar resulted in Sb-retarded diffusion in ion-implanted samples, as compared with non-implanted samples. A vacancy undersaturation in implanted samples appeared in spikes which had been amorphized, as well as in those that were not. This undersaturation may have been due to interstitial-vacancy recombination with excess interstitials from the implantation. When interstitials bounded by the loops were counted, there were only 4 x 1014/cm2 such interstitials in high-fluence samples after being annealed in Ar. Therefore, only 4% of the 1016/cm2 of implanted Si ions were in loops; leaving many interstitials free to recombine with vacancies. Overall, an end-of-range dislocation loop band effectively captured most of the vacancies which were injected by a thermally grown SiNx film at 910C. A vacancy undersaturation was also observed in Si that was amorphized and re-grown.

S.B.Herner, H.J.Gossmann, F.H.Baumann, G.H.Gilmer, D.C.Jacobson, K.S.Jones: Applied Physics Letters, 1998, 72[1], 67-9