Buried amorphous layers were produced in silicon single crystal by lithium implantation at liquid nitrogen temperature and followed by 400C annealing. By using this process, a wide region, perfectly crystalline and free of any extended defect, was formed ahead of the buried amorphous layer up to the implanted surface. Neon was then implanted into this front region to high fluences at 250C in order to create bubbles and avoid further amorphization. In the presence of a buried amorphous layer, a significant decrease in the extended defect density was observed at the neon end-of-range region. The results were explained in terms of interstitial trapping, i.e. the buried amorphous layer acted as an efficient sink for interstitials during recrystallization.

Interaction of Interstitials with Buried Amorphous Layer in Silicon. E.Oliviero, M.L.David, P.F.P.Fichtner: Physica Status Solidi C, 2009, 6[8], 1969-73