Effect of 20 MeV proton irradiation on the electrical properties of <i>β</i>-Ga2O3 Schottky barrier diodes with field plate

Abstract

In this Letter, the impact of 20 MeV proton irradiation on β-Ga2O3 Schottky barrier diodes (SBDs) with field plates has been investigated. After proton irradiation with fluences of 2 × 1012 and 5 × 1012 p/cm2, the forward current density (JF) decreased from 294.0 to 250.5 and 192.0 A/cm2, respectively. The turn-on voltage (Von) increased from 0.78 to 0.82 and 0.84 V, as measured by current–voltage (I–V) testing. Capacitance–voltage (C–V) measurements showed that the net carrier concentration in the lightly doped drift region of β-Ga2O3 decreased from 1.95 × 1016 to 1.83 × 1016 and 1.38 × 1016 cm−3 after proton irradiation. Additionally, C–V measurements at different frequencies reveal that capacitance gradually decreases as proton fluence increases, though the frequency has little effect on capacitance. The effect of proton irradiation on β-Ga2O3 SBDs was also characterized using low-frequency noise and x-ray photoelectron spectroscopy. The results indicated that the voltage noise spectral density (Sv) gradually increases with proton fluence and bias voltage before and after irradiation due to the introduction of defects. This study provides an important reference for the reliability assessment of β-Ga2O3 SBDs.