Impact of electron-beam irradiation on the performance of β-Ga2O3 Schottky barrier diodes

Gallium oxide (Ga2O3) is expected to have high radiation tolerance owing to their strong bond strengths and thus promising for the fabrication of robust electronic devices to be deployed in space missions and nuclear power plants. In this work, we investigated the performance of β-Ga2O3 vertical Schottky barrier diodes (SBDs) before and after electron-beam irradiation up to a cumulative fluence of 1×1016 cm-2. Electron-beam irradiation with an energy of 1.5 MeV and a fixed fluence rate of 4.62×1012 cm-2∙s-1 was carried out in air at room temperature with cumulative fluences of 0 (i.e., before irradiation), 1×1014, 5×1015, and 1×1016 cm-2. The specific on-resistances (Ron) and turn-on voltages (Von) were extracted from linear fits to the forward current density–voltage (J–V) characteristics and extrapolation of the linear fits to J=0 A/cm2, respectively. The Ron increased from 4.1 to 7.0 mΩ∙cm2 as the cumulative fluence increased from 0 to 1×1016 cm-2. The Von were estimated to be 1.8, 1.8, 1.7 and 1.7 V for cumulative fluences of 0, 1×1014, 5×1015, and 1×1016 cm-2, respectively. From linear fits to semi-logarithmic J–V plots, the ideality factors (η) for cumulative fluences of 0, 1×1014, 5×1015, and 1×1016 cm-2 were extracted to be 1.11, 1.10, 1.12 and 1.09, respectively. Insignificant changes in both Von and η implied a negligible effect of irradiation on the Pt/Ga2O3 interface. However, the 73% increase in Ron from 4.1 to 7.0 mΩ∙cm2, which was attributable to a comparable reduction in Nd-Na from 2.3×1016 to 1.2×1016 cm-3 as revealed by C–V measurement, suggested the presence of a high density of electron traps in irradiated Ga2O3.The 3rd International Workshop on Gallium Oxide and Related Materials (IWGO-3