Analyzing Spectral Electroluminescence Sensitivities of SiC MOSFETs and their Impact on Power Device Monitoring

Abstract:
This paper analyzes the spectral sensitivities of SiC MOSFET’s electroluminescence (EL) and evaluates their impact on device monitoring approaches. Previous research demonstrated how the EL of SiC MOSFETs can be used for galvanically-isolated and high-bandwidth temperature and current sensing. However, the sensitivities of the spectrum to effects, such as gate biasing and bias temperature instability (BTI), have not been investigated. For this reason, a deeper understanding and consideration of these effects is essential for the highly accurate application of the proposed sensing approaches in next generation monitoring of SiC converters. Thus, this work identifies key parameters that strongly influence the EL spectrum and examines their sensitivities, which is supported by measurements of an industry-standard power module. Finally, this work presents techniques that compensate the impact of these influences on EL-based monitoring solutions.