Interstitial-type defects away from the projected ion range in high energy ion implanted and annealed silicon

Defects in high energy ion implanted silicon have been investigated, especially in the depth range around half of the projected ion range $RP/2$ after annealing at temperatures between 700 and 1000 °C. Preferable trapping of metals just in this depth range proves the existence of defects there. No vacancy-like defects could be detected by variable energy positron annihilation spectroscopy after annealing at temperatures $T>800 °C.$ Instead, interstitial-type defects were observed in the $RP/2$ region using cross section transmission electron microscopy of a specimen prepared under special conditions. The results indicate the presence of small interstitial agglomerates at $RP/2$ which remain after high temperature annealing.