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.

Heavy-ion microbeams are employed for probing the radiation-sensitive regions in commercial silicon carbide (SiC) vertical double-diffused power (VD)-MOSFETs with micrometer accuracy. By scanning the beam spot over the die, a spatial periodicity was observed in the leakage current degradation, reflecting the striped structure of the power MOSFET investigated. Two different mechanisms were observed for degradation. At low drain bias (gate and source grounded), only the gate-oxide (at the JFET or neck region) is contributing in the ion-induced leakage current. For exposures at drain–source bias voltages higher than a specific threshold, additional higher drain leakage current is observed in the p-n junction region. This provides useful insights into the understanding of basic phenomena of single-event effects in SiC power devices.

Experimental results on ion-induced leakage current increase in 4H-SiC Schottky power diodes are presented. Monte Carlo and TCAD simulations show that degradation is due to the synergy between applied bias and ion energy deposition. This degradation is possibly related to thermal spot annealing at the metal semiconductor interface. This thermal annealing leads to an inhomogeneity of the Schottky barrier that could be responsible for the increase leakage current as a function of fluence.

High sensitivity of SiC power MOSFETs has been observed under heavy ion irradiation, leading to permanent increase of drain and gate leakage currents. Electrical post-irradiation analysis confirmed the degradation of the gate oxide and the blocking capability of the devices. At low drain bias, the leakage path forms between drain and gate, while at higher bias the heavy ion induced leakage path is mostly from drain to source. An electrical model is proposed to explain the current transport mechanism for heavy-ion degraded SiC power MOSFETs.