Neutron irradiation and annealing temperature effects of CZ-Silicon

In the present work, we have irradiated p-type CZ-silicon at two different neutron fluences, 1.98 ×1018 and 3.96 ×1018 n/cm2. The optical properties and irradiation damage have been investigated using Fourier Transform Infrared spectroscopy (FTIR) and UV-VIS spectrophotometer technique at room temperature. The results show that the density of the vacancy-oxygen complex VO center (830 cm-1) increases with increasing neutron fluence. Further, the creation of the divacancy defect (1.8 μm) concentration and the near edge absorption was formed after irradiation. The results from annealing indicate that near-edge absorption, VO defects disappear at 550 °C. However, another band around 825 cm-1 was formed at the same temperature. The near-edge absorption and the band of 1.8μm have not been detected at 550 °C, and new bands near 1.4 and 1.7μm appeared. It is reasonable to assume that the two bands may be due to the divacancy consisting one or more lithium impurity atoms. The existence of these bands confirms that the transmutation of the boron to the lithium atoms can be attained in the neutron fluences available at the reactor Es Salem. It was concluded that the cluster defects induced by the neutron irradiation can be attributed to the vacancy-rich region which reordered after annealing treatment.