Transmission electron microscopy was used to study bubbles and extended defects in crystalline samples which had been implanted with 1.6MeV He to a dose of 1017/cm2, and annealed (800C, 1002s to 17h). Frank dislocation loops were observed, in addition to long rod-like {113} defects, below a bubble layer which was located near to the mean projected range. During initial annealing, only Frank loops which were bound to bubbles were present. The bubble morphology did not change greatly during longer annealing times, but there were marked changes in the extended defects located beyond the band of bubbles. After 0.5h of annealing, Frank loops and {113} defects which resulted from the precipitation of Si interstitials were observed. The dissolution of {113} defects then took place, and only Frank loops remained. The Frank loops were homogeneously distributed at up to 500nm below the bubble layer, and were of equal size. After 17h of annealing, there were no more extended defects beyond the buried layer.

Defects in Silicon Induced by High-Energy Helium Implantation and their Evolution during Anneals. M.F.Beaufort, E.Oliviero, H.Garem, S.Godey, E.Ntsoenzok, C.Blanchard, J.F.Barbot: Philosophical Magazine B, 2000, 80[11], 1975-85