Metallic impurity gettering to defects remaining in the R-P/2 region of MeV-ion implanted and annealed silicon

Damage has been observed in MeV-ion-implanted Si away from the projected io n range, R-p, mainly around R-p/2, after annealing at temperatures between 700 and 1000 degreesC. The most suitable way to detect this damage is to de corate it with metals and to measure the metal distribution. The formation and disappearance of the R-p/2 damage has been investigated by Cu gettering in Si+-ion implanted Si versus temperature and time of the annealing cycle . It is believed that an excess of vacancies around R-p/2 getter metal impu rities. By means of positron annihilation spectroscopy no vacancy defects h ave been detected. In contrast, XTEM investigation reveals small (20-30 nm) interstitial loops in the R-p/2 region. The creation of these loops is tri ggered by interstitials injected during the ion milling procedure used for TEM specimen preparation. The ion bombardment of Si gives rise to self-inte rstitials that may modify the existing interstitial clusters to bigger aggl omerates observable by XTEM. (C) 2000 Elsevier Science Ltd. All rights rese rved.