Damage was observed, mainly at around half of the projected ion range, in MeV ion-implanted samples after annealing at 700 to 1000C. The best method for detecting this damage was to decorate it with metal, and then measure the metal distribution. The formation and disappearance of this damage was investigated by Cu-gettering, in Si+-implanted samples, as a function of annealing temperature and time. It was believed that an excess of vacancies, at around half of the projected ion range, gettered metal impurities. No vacancy defects were detected by means of positron annihilation spectroscopy. On the other hand, XTEM investigations revealed small (20 to 30nm) interstitial loops in the Rp/2 region. The creation of these loops was triggered by interstitials which were injected during the ion milling that was used for transmission electron microscopic specimen preparation. Ion bombardment of Si gave rise to self-interstitials that could modify existing interstitial clusters so as to give bigger agglomerates which were then observable by XTEM.
Metallic Impurity Gettering to Defects Remaining in the Rp/2 Region of MeV-Ion Implanted and Annealed Silicon. A.Peeva, R.Koegler, G.Brauer, P.Werner, W.Skorupa: Materials Science in Semiconductor Processing, 2000, 3, 297-301