Lattice Sites and Stability of Implanted Er in FZ and CZ Si

Abstract

AbstractWe report on the lattice location of 167Er in Si measured by conversion electron emission channeling. In both FZ and CZ Si, a high fraction of Er (>65%) occupies near-tetrahedral interstitial (T) sites directly following 60 keV room temperature implantation at doses of 6× 1012 cm−2 For higher doses, the as-implanted near-T fractions of Er visible by emission channeling are smaller, due to the beginning of amorphization. Following the recovery of implantation damage at 600°C, more than 70% of Er is found on near-T sites in both FZ and CZ Si. In FZ Si, Er exhibits a remarkable thermal stability and only prolonged annealing for several hours reduces the near-T fraction. On the other hand, annealing of CZ Si at 900°C for more than 10 minutes results in the majority of Er probes in sites of very low symmetry or disordered surroundings.