Defects Induced by High-Temperature Neutron Irradiation in 250 µm-Thick 4H-SiC p-n Junction Detector

The objective of the proposed work was to investigate the electrical performance of a 250 mu m-thick 4H-SiC p-n junction detector after irradiation with DT neutrons (14.1 MeV energy) at high temperature (500 degrees C). The results showed that the current-voltage (I-V) characteristics of the unirradiated SiC detector were ideal, with an ideality factor close to 1.5. A high electron mobility (mu n) and built-in voltage (Vbi) were also observed. Additionally, the leakage current remained very low in the temperature range of 298-523 K. High-temperature irradiation caused a deviation from ideal behaviour, leading to an increase in the ideality factor, decreases in the mu n and Vbi values, and a significant rise in the leakage current. Studying the capacitance-voltage (C-V) characteristics, it was observed that neutron irradiation induced reductions in both Al-doped (p+-type) and N-doped (n--type) 4H-SiC carrier concentrations. A comprehensive investigation of the deep defect states and impurities was carried out using deep-level transient spectroscopy (DLTS) in the temperature range of 85-750 K. In particular, high-temperature neutron irradiation influenced the behaviours of both the Z1/2 and EH6/7 traps, which were related to carbon interstitials, silicon vacancies, or anti-site pairs.