Defects in Ge and Si caused by 1 MeV Si⁺ implantation

Cross-sectional transmission electron microscopy was used to study defect formation and evolution in the (001) Ge and Si wafers implanted with 1 MeV Si+ and 40 keV Si+ at a dose of 1× 1014 cm-2. As expected, upon annealing, the {311} extended defects form and subsequently dissolve at the projected range for nonamorphizing implants into Si. However, in Ge, no {311} defect formation is observed for this nonamorphizing implant after annealing at temperatures between 350 and 850 °C. Instead, for the MeV implant, small dotlike defects are observed in Ge, which dissolve upon annealing between 650 and 750 °C for 10 min.