Oxygen-related vacancy-type defects in ion-implanted silicon

Czochralski silicon samples implanted to a dose of 5 x 10(15) cm(-2) with 0.5 MeV O and to a dose of 10(16) cm(-2) with 1 MeV Si, respectively, have been studied by positron annihilation spectroscopy. The evolution of divacancies to vacancy (V)-O complexes is out-competed by V-interstitial (1) recombination at 400 and 500degreesC in the Si- and O-implanted samples; the higher oxygen concentration makes the latter temperature higher. The defective region shrinks as the annealing temperature increases as interstitials are injected from the end of the implantation range (R-p). VmO, (m > n) are formed in the shallow region most effectively at 700degreesC for both Si and 0 implantation. VmOn (x < y) are produced near Rp by the annealing. At 800degreesC, implanted Si ions diffuse and reduce m and implanted 0 ions diffuse and increase n in VmOn. All oxygenrelated vacancy-type defects appear to begin to dissociate at 950degreesC, with the probable formation of oxygen clusters. At 1100degreesC, oxygen precipitates appear to form just before R-p in O-implanted silicon.