The effect of external gettering, using a reverse-side Al-Si alloy, upon the recombination strength of dislocation arrays was investigated. The arrays were made by scratching and bending float-zone wafers (750C, 6h). Light beam-induced current maps showed that the recombination strengths of these defects were sharply reduced at room temperature when the sample was submitted to external gettering by Al-Si alloying at 900C. This was attributed to the removal of metallic impurities from dislocations and by their capture, in the Al-Si alloy, via a segregation-induced gettering mechanism.

S.Martinuzzi, I.Perichaud, J.J.Simon: Applied Physics Letters, 1997, 70[20], 2744-6