use of type II (end of range) damage as “detectors” for quantifying ititerstitial fluxes in ion-implanted silicon

Type-II (end of range) defects, produced by Ge+ implantation, were investigated as possible “detect0rs” for quantifying nonequilibrium interstitial concentrations following Bt implantation into silicon. The type-11 damage was created with a 100 keV ( 1 x 1015/cm2) Get implant into silicon followed by either a low-temperature (550 “C) or a high-temperature (800 “C) anileal. This resulted in the formation of either a layer of point-defect clusters and small ( x 50 A in diameter) dislocation loops or a layer of larger ( 160-400 8, in diameter) fully formed dislocations loops. This material was subsequently implanted with 30 keV B+ at. doses between 7 X 10’3/cm2 and 2 x 10”/cm2. After a final 800 “C anneal, the concentration of atoms bound by the type-11 dislocation loops was measured. Results show that the concentration of interstitials bound by the type-11 dislocation loops increases with increasing B + dose. Relative to control sample values, the net concentration of interstitials trapped as a result of B+ implantation varied from 7.0X 1013/cm2 to 1.8X 10’4/cm2 over the dose range studied. Fully formed loops were also found to be >20% more efficient than clusters in trapping the interstitials generated under identical B+ implant conditions. The difference is ascribed to the increase in equilibrium point-defect concentration necessary to stabilize the smaller loops prior to coarsening.