Comparison of 10 MeV Neutron Irradiation Effects on NiO/Ga2O3 Heterojunction Rectifiers and Ni/Au/Ga2O3 Schottky Rectifiers

Neutrons generated through charge-exchange 9Be (p; ni) 9Be reactions, with energies ranging from 0–33 MeV and an average energy of ∼9.8 MeV were used to irradiate conventional Schottky Ga2O3 rectifiers and NiO/Ga2O3 p-n heterojunction rectifiers to fluences of 1.1–2.2 × 1014 cm−2. The breakdown voltage was improved after irradiation for the Schottky rectifiers but was highly degraded for their NiO/Ga2O3 counterparts. This may be a result of extended defect zones within the NiO. After irradiation, the switching characteristics were degraded and irradiated samples of both types could not survive switching above 0.7 A or 400 V, whereas reference samples were robust to 1 A and 1 kV. The carrier removal rate in both types of devices was ∼45 cm−1. The forward currents and on-state resistances were only slightly degraded by neutron irradiation.