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

This study investigates 1 MeV electron irradiation affects 4H-SiC junction barrier Schottky (JBS) 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 (Rs), Schottky barrier height and carrier concentration. Defects were detected using deep-level transient spectroscopy (DLTS), photoluminescence (PL), and optically detected magnetic resonance (ODMR). Results show that Rs first decreases at low irradiation fluences because carbon interstitials (IC), silicon vacancies (VSi) and silicon interstitials (ISi) reduce carbon vacancy (VC) concentration, improving carrier mobility. At higher fluences, Rs increases due to acceptor-level defects reducing carrier concentration. Reverse leakage current (Ir) changes nonlinearly with fluence: (1) Generation-recombination current increases due to more VC, VSi, and complex defects in the bulk; (2) Thermionic emission and tunneling currents decrease. The combined effects lead to complex leakage behavior. VSi 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.