Defect and electrical characteristics of 4H-SiC junction barrier Schottky diodes under high-energy electron irradiation at different fluences

Abstract This study investigates 1 MeV electron irradiation affects 4H-SiC junction barrier Schottky diodes by analyzing defects and electrical parameters. Current voltage ( I – V ) and capacitance voltage ( C – V ) measurements are used to extract parameters such as series resistance ( R s ), Schottky barrier height and carrier concentration. Defects were detected using deep-level transient spectroscopy, photoluminescence, and optically detected magnetic resonance. Results show that R s first decreases at low irradiation fluences because carbon interstitials ( I C ), silicon vacancies ( V Si ) and silicon interstitials ( I Si ) reduce carbon vacancy ( V C ) concentration, improving carrier mobility. At higher fluences, R s increases due to acceptor-level defects reducing carrier concentration. Reverse leakage current ( I r ) changes nonlinearly with fluence: (1) Generation-recombination current increases due to more V C , V Si , and complex defects in the bulk; (2) Thermionic emission and tunneling currents decrease. The combined effects lead to complex leakage behavior. V Si play a critical role in both defect compensation and recombination processes. This work provides practical guidance for designing radiation-resistant SiC devices in space applications.