Deep-level transient spectroscopy was used to study defect accumulation in n-type material which had been implanted with 135keV B ions, to doses which ranged from 1011 to 3 x 1013/cm2, at room temperature. It was found that the deep levels that were typical of neutron-irradiated material were observed in the ion-implanted crystals only after doses of less than 1012/cm2. Changes in the deep-level transient spectra were attributed to defect cluster transformations (such as growth) which preceded amorphization. The dose which was required to cause the changes in the deep-level transient spectra was increased if the crystal contained impurities, such as O, which actively interacted with the point defects. The dose was equal to 3 x 1011 and 3 x 1012/cm2 for float-zone and Czochralski material, respectively, when the P dopant content was 4 x 1015/cm3.

I.V.Antonova, S.S.Shaimeev: Physica Status Solidi A, 1996, 153[2], 329-36