Heavy-ion induced single-event burnout (SEB) is investigated in high-voltage silicon carbide power MOSFETs. Experimental data for 1200 V SiC power MOSFETs show a significant decrease in SEB onset voltage for particle LETs greater than 10 MeV-cm2/mg, above which the SEB threshold voltage is nearly constant at half of the rated maximum operating voltage for these devices. TCAD simulations show a parasitic BJT turn-on mechanism, which drives the avalanching of carriers and leads to runaway drain current, resulting in SEB.

Heavy ion data suggest that a common mechanism is responsible for single-event burnout in 1200 V power MOSFETs and junction barrier Schottky diodes. Similarly, heavy ion data suggest a common mechanism is also responsible for leakage current degradation in both devices. This mechanism, based on ion-induced, highlylocalized energy pulses, is demonstrated in simulations and shown to be capable of causing degradation and singleevent burnout for both the MOSFETs and JBS diodes.

Ion-induced degradation and catastrophic failures in high-voltage SiC junction barrier Schottky power diodes are investigated. The experimental results agree with earlier data showing discrete jumps in leakage current for individual ions and show that the boundary between leakage current degradation and a single-event-burnout-like effect is a strong function of linear energy transfer and reverse bias. TCAD simulations show high localized electric fields under the Schottky junction, and high temperatures generated directly under the Schottky contact, consistent with the hypothesis that the ion energy causes eutectic-like intermixture at the metal-semiconductor interface or localized melting of the silicon carbide lattice.

Ion- and terrestrial neutron-induced single-event burnout (SEB) data indicate that a thicker, more lightly doped epitaxial (epi) region significantly increases the threshold at which ion-induced SEB occurs in silicon carbide (SiC) power MOSFETs and junction barrier Schottky (JBS) diodes. Simulations indicate that the reduction of power dissipation along the core of the ion track is responsible for the increased robustness of the devices that have higher breakdown voltage ratings. Implications for circuit design show that using a 3300-V power MOSFET provides a significant increase in SEB threshold margin compared to a 1200-V MOSFET, with minor impact on power dissipation during normal operation.

Cross sections and failure in time rates for neutron-induced single-event burnout (SEB) are estimated for SiC power MOSFETs using a method based on combining results from heavy ion SEB experimental data, 3-D TCAD prediction of sensitive volumes, and Monte Carlo radiation transport simulations of secondary particle production. The results agree well with experimental data and are useful in understanding the mechanisms for neutron-induced SEB data.

Low-energy ion-induced breakdown and single-event burnout are experimentally observed in β-Ga ₂ O ₃ Schottky diodes with voltages well below those of expected electrical breakdown. Fundamentally different responses were observed among alpha-particle, Cf-252, and heavy-ion irradiation. TCAD simulations suggest that ion-induced burnout can be triggered at high voltages as a result of a single ion strike, leading to impact ionization, voltage-induced charge separation accentuated by the low intrinsic hole mobility in β-Ga ₂ O ₃ , and breakdown. At significantly lower voltages, the cumulative buildup of displacement-damage-induced defects in β-Ga ₂ O ₃ during high-fluence ion irradiation can lead to defect-driven breakdown due to the generation and motion of negatively charged Ga vacancies and O interstitials. First-principles calculations show that defect clusters can be formed that are much less resistive than the surrounding material. These clusters can be driven deeply into the device by the reverse bias, ultimately forming conduction paths that can facilitate the destruction of the device at reduced voltages.