Effect of Low-Dose Irradiation and Subsequent Isochronous Annealing on the Current-Voltage Characteristics of Silicon Carbide-Based Surface-Barrier Diodes

A study was conducted on the effect of low-dose (~10¹⁶ cm^–2) irradiation with electrons with an energy of 0.9 MeV and subsequent isochronous annealing at temperatures up to 550°C on the current-voltage characteristics of commercial rectifier diodes based on 4H-SiC with a doping level of (3–7) × 10¹⁵ cm^–3. The previously established effect of increasing series resistance R_s of diodes under irradiation, the numerical value of the threshold dose of irradiation, and the effect of the spread of the value of R_s of identical diodes at the same dose of radiation have been confirmed. For the first time, isochronous annealing (without passing current during annealing) was performed at temperatures up to 550°C, significantly exceeding the maximum operating temperatures of the diodes. It has been shown that starting from temperatures ≥200°C the annealing of defects is observed, which is expressed in a decrease in the value of R_s at room temperature down to pre-irradiation values. Annealing also leads to a decrease in the reverse breakdown current.