Radiation hardness of SiC subjected to alternating irradiation and annealing

Effect of the cycle “introduction of defects, annealing, and repeated introduction of defects” on the SiC properties has been studied by means of nuclear spectrometry for an example of degradation of characteristics of a p-n nuclear radiation detector. The defects were introduced by irradiation with 8-MeV protons in two equal fluences of 3 × 10 14 cm −2 . The total fluence of 6 × 10 14 cm −2 corresponded to an introduction of 2.4 × 10 17 cm −3 primary knocked-out atoms. The annealing was made in two stages, each 1 h long, at temperatures of 600 and 700 °C. The detectors were tested with 5.4-MeV α particles, with the charge collection efficiency and specific features of the amplitude spectrum determined. The measurements were performed in the temperature range of 20–250 °C. It was shown that the effect of the first irradiation and the subsequent annealing does not significantly change the radiation hardness of SiC. The effective concentration of centers introduced in the course of the second irradiation (at the same fluence) is higher by a factor of 1.2. The nonequivalence of the fluences can also be attributed to the effect of the high total proton fluence of 6 × 10 14 cm −2 .