Annealing effects on p+n junction 4H-SiC diodes after very high neutron irradiation

In this work we analyzed the annealing effects on SiC p+n diodes used as minimum ionizing particle (MIP) detectors after very high 1 MeV neutron fluences. After the highest neutron fluences the samples were heavily damaged. The samples underwent thermal cycles at 80°C, 200°C and 400°C to verify if a damage recovery occurs in irradiated samples. A noticeable reduction of the leakage current density occurred after 30 min at 80°C and then remained almost constant even after many hours of annealing. Regarding the collected charge, after thermal cycles at 80°C we observe a slight increase, but in the range of the experimental error. After an annealing at 200°C for 30 min we have a partial recovery of the damage with an increase of the collected charge of 400 e- (from 1800 e- to 2200 e-). After 30 min at 400°C the leakage current further decreases while the collected charges increase of 40% with respect to the amount of charges collected before annealing.