Study on the mechanism of performance degradation in β-Ga2O3 heterojunction diodes under 10 MeV proton irradiation

In this Letter, the performance degradation mechanisms of β-Ga2O3 heterojunction diodes (HJDs) under 10 MeV proton irradiation have been investigated. After proton irradiation with a fluence of 1 × 1013 p/cm2, the forward current density (JF) decreased by 9.9%, the specific on-resistance (Ron, sp) increased from 16.2 to 18.0 mΩ cm2, and the breakdown voltage (Vbr) increased by approximately 310 V. The results of the electrical stress test indicate that the JF of HJDs gradually decreases as the duration of the applied electrical stress increases. Low-frequency noise measurements were carried out in order to characterize the defects introduced into the HJDs after proton irradiation. Meanwhile, to further elucidate the underlying damage mechanism of HJDs, the effect of proton irradiation on the trap states was also studied using frequency-dependent conductivity (Gp/ω) techniques. The results indicate that the density of trap states at NiO/β-Ga2O3 increases from 2.08–9.78 × 1011 cm−2 eV−1 to 1.25–2.87 × 1012 cm−2 eV−1, accompanied by a slight increase in trap activation energy from 0.0042–0.061 to 0.0265–0.075 eV after 10 MeV proton irradiation. The research outcomes provide an important theoretical reference for evaluating the space radiation tolerance of Ga2O3-based power diodes.