Interactions between end-of-range dislocation loops and {311} defects were studied as a function of their proximity. The dislocation loops were introduced by dual implantation of 30keV Si+ to 1015/cm2 and 120keV Si+ to 1015/cm2, followed by annealing (850C, 0.5h). The depth of the loop layer from the surface was varied from 260 to 180 or 100nm by polishing away the surface. Post-polishing implantation (40keV Si+ to 1014/cm2) was used to create point defects at the projected range of 58nm. The wafers were annealed at 700, 800 and 900C, and studied using plan-view transmission electron microscopy. It was found that the number of interstitials in {311} defects decreased as the projected range damage was brought closer to the loop layer, while the number of rectangular elongated defects increased. Further investigation showed that the rectangular elongated defects were formed at the end-of-range. It was concluded that interstitials which were introduced at the projected range were trapped at the end-of-range. The rectangular elongated defects then formed due to interactions between interstitials and pre-existing dislocation loops.

Effect of the end-of-range loop layer depth on the evolution of {311} defects R.Raman, M.E.Law, V.Krishnamoorthy, K.S.Jones: Applied Physics Letters, 1999, 74[5], 700-2