Reliability of SiC Power Devices against Cosmic Ray Neutron Single-Event Burnout

Abstract

High-energy neutrons produced by cosmic ray interactions with our atmosphere are known to cause single-event burnout (SEB) failure in power devices operating at high fields. We have performed accelerated high-energy neutron SEB testing of SiC and Si power devices at the Los Alamos Neutron Science Center (LANCSE). Comparing Wolfspeed SiC MOSFETs having different voltage (900V – 3300V) and current (3.5A – 72A) ratings, we find a universal behavior when scaling failure rates by active area, and scaling drain bias by avalanche voltage. Moreover, diodes and MOSFETs behave similarly, revealing that the SiC drift dominates the failure characteristics for both device types. This universal scaling holds for SiC MOSFETs from other manufacturers as well. The SEB characteristics of Si power IGBT and MOSFET devices show that near their rated voltages failure rates of Si devices can be 10X higher than that of comparable SiC MOSFET devices. Thus, Si devices are more susceptible to SEB failure from voltage overshoot conditions.