CIAE, Beijing, People’s Republic of China
In this study, the influence of proton irradiation experiments at 40 MeV and p/cm2 on Silicon Carbide Junction Barrier Schottky (SiC-JBS) diodes with stripe cell and hexagonal cell designs was investigated, respectively. Considering the displacement damage effect of SiC-JBS diodes, the experiments was implemented on unbiased SiC-JBS diodes based on 100 MeV high intensity proton cyclotron of China Institute of Atomic Energy. The results show that the current voltage (IV) and capacitive voltage (CV) characteristics of the SiC-JBS diodes are obviously degraded by proton irradiation. After 168 h of room temperature annealing, the forward IV characteristics of the SiC-JBS diodes are basically restored but the reverse leakage current is increased. After 336 h of room temperature annealing, the forward IV characteristic of the diodes is completely restored, but the reserve IV characteristic of the diodes with stripe cell is completely restored. And the CV characteristic is degraded of the two kinds of SiC-JBS diodes permanently, which indicating that room temperature annealing cannot restore the proton radiation displacement damage defects. Combined with Monte Carlo simulations, it is shown that proton irradiation will introduce ionization defects and displacement defects into the SiC-JBS diodes, in which the disappearance of displacement damage defects will eventually lead to the degradation of electrical properties of reverse IV and CV. The analysis of the SiC-JBS diodes structure shows that, without considering the diode materials and process level, the SiC-JBS diode with hexagonal cells is more resistant to proton irradiation displacement damage and has stronger room temperature annealing self-repair ability than the SiC-JBS diodes with stripe cells, even though its chip area is smaller. On the other hand, the SiC-JBS diodes with hexagonal cells can be used preferentially in the radiation environment where there is a large amount of proton.
