Displacement damage effect of proton irradiation on vertical β-Ga₂O₃ and SiC Schottky barrier diodes (SBDs)

In this study, we fabricated vertical Schottky barrier diodes (SBDs) based on wide bandgap semiconductor beta-phase gallium oxide (β-Ga₂O₃) and silicon carbide (SiC), respectively, and conducted proton irradiation experiments to analyze the radiation hardness of the SBDs comparatively. The effects of proton radiation on the performance of SBDs were assessed through measurements of forward current, capacitance, and breakdown characteristics. Both devices exhibited degradation in current and capacitance characteristics following proton irradiation, attributed to displacement damage (DD). Notably, the β-Ga₂O₃-based SBD demonstrated more pronounced deterioration compared to the SiC-based device despite similar vacancy distributions as confirmed by SRIM simulation. Moreover, a decrease in contact radius correlated with exacerbated degradation in the current characteristics of the β-Ga₂O₃-based SBD. Following proton irradiation, breakdown voltages of both devices increased due to elevated resistance induced by displacement damage. While both β-Ga₂O₃ and SiC-based SBDs experienced displacement damage under high fluence proton irradiation, the extent of performance degradation varied depending on the dimensions and quality of epitaxial and substrate layers.