Lifetime studies of deeply penetrating defects in self-ion implanted silicon

Carrier lifetime measurements have been used to characterise residual defects after low-energy implanting of silicon ions followed by high temperature annealing (900 or 1000°C). The implant was found to result in two distinct regions of lifetime-reducing damage. Firstly, a high recombination region, most likely due to stable dislocation loops, remained near the surface. In addition, deeply propagated defects, which were not present prior to annealing, were also detected. These deep defects, which are possibly silicon interstitials, diffuse so rapidly during annealing that their distribution becomes effectively uniform to a depth of 100 microns. Annealing at higher temperatures was found to reduce the severity of both the surface and the deeply propagated defects