Abstract: The ultra-wide bandgap semiconductor β-Ga₂O₃, with high critical breakdown field and displacement threshold energy, show great potential for applications in harsh irradiation space environments. However, due to the low thermal conductivity and hole mobility, high-energy particle irradiation could lead to single-event burnout (SEB) far below the rated voltage. Therefore, this work proposes to transfer the peak electric field from the drift layer surface at the anode edge to the sidewall of the mesa termination, which prevents the further aggravation of electric field crowding at Schottky contact under the single-event effects (SEE). Moreover, the localized power density was reduced to increase the SEB threshold. The 1.86 GeV tantalum ions with the linear energy transfer (LET) exceeding 80 MeV·cm²·mg^-1 are adopted in our experiment. The SEB voltage of the termination-less Schottky barrier diode (SBD) is only 170 V, while the SEB threshold of SBD with mesa termination reaches 220 V. The SEE transient response of the devices was investigated by coupling electro-thermal model. The simulation results indicate that the peak electric field at the drift layer surface is significantly suppressed and the low peak electric field prevents the excessive local power dissipation to reduce the internal peak temperature of the device, and increases the SEB threshold. This work provides a new approach for the irradiation hardening method ofβ-Ga₂O₃ power devices.

Key words: β-Ga₂O₃, Schottky barrier diode, mesa termination, irradiation, single-event effect