It was noted that the recombination strength of extended crystallographic defects in Si depended strongly upon their interaction with impurities such as O, as well as metallic atoms, which could be trapped by the defects. This trapping was likened to an internal gettering mechanism. Attention was focussed here on dislocations which were generated by the plastic deformation of scratched monocrystals. The light-beam induced current technique, involving various wavelengths, was used to detect the presence of defects and to evaluate their recombination strength. It was found that, in float-zone wafers, the recombination strength of the dislocations was due mainly to an accidental contamination of the samples during deformation. The presence of P markedly reduce the recombination strength. When P in-diffusion was applied to Czochralski-type wafers, a competition occurred between external gettering, and internal gettering due to O which was segregated along the dislocations.

I.Périchaud, S.Martinuzzi: Solid State Phenomena, 1997, 57-58, 103-8