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

摘要

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_(annea.)≈ 260 – 280°C 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 Tanneal.≥ 520°C. The annihilation gamma-quanta to be emitted from the positron trap gives rise to a characteristic positron lifetime τ2(I_2 ～ 38–19 %) ≤ 276 – 294 ps which is somewhat longer than the one predicted for unrelaxed single vacancy τV.≈ 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, Vs-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.