The effects of co-doped O and thermal annealing upon the evolution of Er lattice sites were reported. At low concentrations of co-doped impurities, it was found that Er preferred to occupy the tetrahedral interstitial site following implantation. The use of O co-doping could greatly encourage implanted Er atoms to occupy the hexagonal interstitial site. In the presence of O, the Er could be stabilized at the hexagonal site during annealing at up to 900C. Post-implantation annealing could markedly promote the occupation of the hexagonal site by Er in O-deficient material; even though few Er atoms were found to be in the hexagonal site following Er implantation.

Evidence of Oxygen-Stabilized Hexagonal Interstitial Erbium in Silicon. M.B.Huang, X.T.Ren: Physical Review B, 2003, 68[3], 033203 (4pp)