The effect of neutron irradiation defects on electrical resistivity in FZ-silicon samples irradiated at Es-Salam research reactor

This paper reports the effect of neutron irradiation defects on electrical properties of n-type FZ-silicon via the measurements of electrical resistivity. For this purpose, FZ-silicon single crystal was irradiated with neutron fluences ranging between 1.54 × 1016 and 2.5 × 1018 cm−2. The samples irradiated at F1 = 1.54 × 1016 cm−2, F2 = 7.43 × 1017 cm−2 and F3 = 2.5 × 1018 cm−2 were isochronally annealed from room temperature up to 750 °C. It is found that, for fluences ranging respectively from 1.54 × 1016 cm−2 to 1.23 × 1017 cm−2 (stage I) and from 3.09 × 1017 cm−2 to 2.5 × 1018 cm−2 (stage II) the resistivity is linearly related to the neutron fluence with two different slopes. The annealing temperature dependence on the electrical resistivity fits well the relationρ0 exp(−CT), where C is a constant depending on the neutron fluence and ρ0 is approximately equal to the resistivity after irradiation. For annealing temperatures higher than 550 °C, we have found that the resistivity is a decreasing function with respect to the neutron fluence and the transmutation-doped phosphorus atoms become electrically active.