Peculiarities of radiation defect accumulation under high-flux γ-ray and electron irradiation of silicon

Abstract

The change of charge-carrier concentration is studied when irradiating floated zone n- and p-type Si with ϱ = (1 to 5) × 102 and (1 to 60) × 103 ω cm by high fluxes of 60Co γ-rays (Φe = 1 × 1017 to 2 × 1019 cm−2) and electrons with energy Ee = 4 to 10 MeV (Φe = 1 × 1015 to 5 × 1016 cm−2). The temperature dependences of the Hall coefficient are measured. The analysis of the results on the accumulation under irradiation and annealing of radiation defects allows one to conclude that various trends of the dose dependences of hole concentration with the kinds of bombarding particles used are due to the difference in the production efficiencies of radiation defects under electron and γ-ray irradiation. The possibility of formation of phosphorus-two vacancy complexes by adding vacancies to E-centres during prolonged γ-irradiation is shown while electrons produce preferentially divacancies. Phosphorus-two vacancy complexes are stable up to T = 400 to 500 °C and introduce a deep acceptor level at Ev + 0.35 eV into the forbidden gap of Si. It is found that the annealing character of radiation defects in heavily irradiated Si does not depend on the kind of irradiation and is due to the rearrangements of intrinsic structural defects. [Russian Text Ignored].