10 MeV proton damage in β-Ga2O3 Schottky rectifiers

The electrical performance of vertical geometry Ga2O3 rectifiers was measured before and after 10 MeV proton irradiation at a fixed fluence of 1014 cm−2, as well as subsequent annealing up to 450 °C. Point defects introduced by the proton damage create trap states that reduce the carrier concentration in the Ga2O3, with a carrier removal rate of 235.7 cm−1 for protons of this energy. The carrier removal rates under these conditions are comparable to GaN-based films and heterostructures. Even annealing at 300 °C produces a recovery of approximately half of the carriers in the Ga2O3, while annealing at 450 °C almost restores the reverse breakdown voltage. The on/off ratio of the rectifiers was severely degraded by proton damage and this was only partially recovered by 450 °C annealing. The minority carrier diffusion length decreased from ∼340 nm in the starting material to ∼315 nm after the proton irradiation. The reverse recovery characteristics showed little change with values in the range 20–30 ns before and after proton irradiation.