Degradation of vertical GaN diodes during proton and xenon-ion irradiation

We investigated the material stability of a vertical GaN Schottky barrier diode (SBD) against proton irradiations by making real-time measurements. The reverse current gradually decreased with increasing proton fluence. The current of the GaN SBD was reduced by 18% after proton irradiations with a displacement-damage dose ( D d ) of 10 12 MeV g −1 . We also examined signal and current degradation occurring in a vertical GaN-on-GaN p–n diode (PND) during xenon-ion irradiations. The signal gradually decreased with increasing xenon-ion fluence. Xenon-ion irradiations of D d = 10 12 MeV g −1 reduced the collected charge in the PND by 11%. This signal degradation was close to the current degradation in the GaN SBD caused by the proton irradiations. We found that irradiations with D d > ∼10 12 MeV g −1 degraded the performance of the GaN devices.