Single-Event Burnout in Vertical β-Ga₂O₃ Diodes With Pt/PtOₓ Schottky Contacts and High-k Field-Plate Dielectrics

Single-event burnout (SEB) is experimentally observed in structurally improved vertical Beta-gallium oxide ( $\beta $ -Ga2O3) Schottky barrier diodes (SBDs) with Pt/PtOx Schottky contacts and high-k field-plate (FP) dielectrics. These SBDs are resistant to alpha particle strikes up to the in-air reverse bias voltage of 475 V, but SEB-induced catastrophic failure is observed during Californium-252 (Cf-252) fission fragment exposure at 400 ± 20 V reverse bias. The SEB threshold in Cf-252 testing is improved in PtOx-contact SBDs with 4- $\mu \text{m}$ epitaxial layers and high-k FP dielectrics by ~30%, compared to previously reported results for Pt-contact SBDs with 10- $\mu \text{m}$ epitaxial layers. TCAD simulations show that ion-induced electric fields increase less in devices with FPs than in those without FPs.