Analysis of the Surge Capability and Degradation Characteristics of 1.2 kV SiC MOSFETs with embedded SBD

Abstract:
We investigate the surge capability and body diode degradation characteristics of 1.2 kV SiC MOSFETs with integrated Schottky barrier diodes (SBDs) in comparison to conventional 1.2 kV SiC MOSFETs. The embedded SBD of the MOSFET can mitigate bipolar degradation and enhance switching charac-teristics. However, the MOSFETs with embedded SBD have unstable reliability when subjected to rap-idly applied high magnitude of surge currents. We focus on these characteristics, carried out the test about the single-pulse surge current test with varying magnitudes of surge current at body diode of the SBD-embedded MOSFETs to evaluate their surge robustness under harsh conditions. Additionally, the failure mechanism about surge capability was analyzed through leakage current measurements and de-capped device inspections to investigate the failure spot. Moreover, the body diode degradation char-acteristics were examined by applying repeated surge currents with varying cycles and magnitudes. The results demonstrate that MOSFETs with embedded SBD exhibit noticeable less degradation under harsh test conditions but relatively unstable surge capability.