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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.

In this article, enhancement-mode (E-mode) operation is achieved by employing a trench gate on the $\beta $ -Ga2O3 current aperture vertical MOSFETs via Sentaurus TCAD simulation. The performance of the trench gate $\beta $ -Ga2O3 MOSFETs was investigated with different structure parameters, such as trench gate depth, channel doping concentration, and drift layer doping concentration and thickness. The transistor with a trench gate recess (Gr) of 130 nm obtained a high on/off current ratio of $10^{8}$ , an on-current density of 65 A/cm2, a low specific on-resistance ( $\text{R}_{\mathrm {on,sp}}$ ) of 42.5 $\text{m}\Omega \cdot $ cm2, and a breakdown voltage (BV) of 488 V for an E-mode operation. With the thickness of the drift layer increasing to $9.2 \mu \text{m}$ , BV is improved to 721 V, $\text{R}_{\mathrm {on,sp}}$ keeps a low value of 43.5 $\text{m}\Omega \cdot $ cm2 due to the trench gate structure, and the transfer characteristic maintains the same. The thermal characteristics of the proposed MOSFET were studied and the device stability with high temperature was analyzed. The transistor with Gr = 130 nm can keep working in E-mode operation at T = 500 K. The performance of the transistor exhibits its great potential as a high-voltage switch device for power electronic applications.