CHARACTERIZATION OF (P-31)+-IMPLANTED SI LAYERS BY ELLIPSOMETRY

Ellipsometry has been used to investigate damage in 1013-10 16/cm2 31P+-implanted Si and crystallinity recovery by subsequent annealing. Implantation-induced changes in optical constants, calculated from measured ellipsometric data, become prominent for implantation over the critical dose for amorphization. The refractive index increases with increasing implant dose, except when the implant dose exceeds 1015/cm2. The extinction coefficient increases monotonically with increasing implant dose and decreasing implant temperature. The dose dependence of the change in reflectivity shows a good agreement with the results by channeling effect analysis. For a sample implanted over the critical dose, optical constants and sheet resistances rapidly recover after annealing at around 500 °C, corresponding to epitaxial regrowths of implantation-induced amorphous layers.