The recombination strength of the dislocations which were created in Czochralski-type wafers was determined by means of light-beam induced current and minority carrier diffusion-length mapping. Dislocation networks were created by scratching and plastic deformation (750C, 6h). The distribution of dislocation was found by means of X-ray topography and/or chemical etching. It was found that the light-beam induced current and diffusion-length measurements revealed the presence of dislocation networks. However, the contrast between dislocated and non-dislocated regions tended to be poor; due to the formation of O precipitates. Preliminary P diffusion, at 900C, modified the material. That is, the precipitates disappeared and a marked contrast was revealed between homogeneous regions of the sample and defect-containing areas. It was suggested that the injection of self-interstitials by P diffusion could explain the results.

I.Périchaud, J.J.Simon: Solid State Phenomena, 1996, 51-52, 117-22