⁶⁰Co gamma ray damage in homoepitaxial β-Ga₂O₃ Schottky rectifiers

β-Ga₂O₃ Schottky rectifiers consisting of thick (10 μm) epitaxial drift regions on conducting substrates are shown to have a high tolerance to ⁶⁰Co gamma ray irradiation. This is due to the low carrier removal rate of <1 cm⁻¹ for gamma rays, which contrasts to values of 300–500 cm⁻¹ for MeV protons and alpha particles in the same rectifier structures. Changes in diode ideality factor, Schottky barrier height, on-resistance, on-off ratio, and reverse recovery time are all minimal for fluences up to 2 × 10¹⁶ cm⁻2 (absorbed dose of 100 kGy (Si)). These results are consistent with previous reports on gamma-irradiation of Ga₂O₃ metal oxide semiconductor field effect transistors (MOSFETs) where changes were ascribed to damage in the gate dielectric and not to the Ga₂O₃ itself.