Similarity of Atomic Configurations of Thermally Stable Positron-Sensitive Complexes Produced with 0.9-MeV Electrons and 15-MeV Protons in n–FZ–Si:P Crystals

We observed for the first time the thermally stable point positron-sensitive center of a vacancy type in n– FZ – Si (P) material irradiated at RT by ~ 0.9-MeV electrons. The center that emerges after isochronal annealing at T anneal. ≈ 260 – 280 oC is found to be similar to the vacancy-group-V-atom complex revealed in the same Si material irradiated by 15-MeV protons; the detecting of the centers by the positron trapping is finalized at T anneal. ≥ 520 oC. The annihilation gamma-quanta to be emitted from the positron trap gives rise to a characteristic positron lifetime τ 2 (I 2 ~ 38–19 %) ≤ 276 – 294 ps which is somewhat longer than the one predicted for unrelaxed single vacancy τ V . ≈ 254 – 261 ps. Our data suggested a configuration of the complex V op PV op , wherein the atom of phosphorus is tied to a split open vacancy volume 2V op . It is argued that V op volume detected by the positron trapping may be formed by extended semi-vacancy, V s -ext , or by the relaxed inwards vacancy, V inw , thus resulting in a distorted V s -ext PV s -ext or V inw PV inw configurations.