Effects of Epitaxial Layer Thickness on Heavy Ion-Induced Single-Event Burnout in Vertical β-Ga₂O₃ Schottky Barrier Diodes

Vertical beta-gallium oxide ( $\beta $ -Ga2O3) Schottky barrier diodes (SBDs) with field plates (FPs) and edge termination structures are irradiated with heavy ions, O+, Ar+, and Pr+ having linear energy transfer (LET) of 5.5–46 MeV $\cdot $ cm2/mg and californium-252 (Cf-252), which emits heavy ions and alpha particles. Devices that have the same structure and similar doping concentrations, but thicker ( $10~\mu $ m) epitaxial layers, show higher single event burnout (SEB) voltage thresholds than devices with thinner ( $4~\mu $ m) epitaxial layers. Ions that stop near the middle of the active region and those that pass through the entire region each cause catastrophic failure in these devices in contrast to previous results on silicon carbide (SiC) SBDs with similar epitaxial layer thicknesses. Cf-252 provides a low-LET, quick screening source for space applications of $\beta $ -Ga2O3 SBDs. However, significantly lower SEB voltage thresholds are observed during high-LET, longer range, Pr heavy-ion testing. The edge region is found to be most vulnerable to SEB for these $\beta $ -Ga2O3 SBDs.