International audienceUnder realistic switching conditions, SiC MOSFETs reliability issues remain as a challenge that requires further investigation. In this letter, a specific aging test has been developed to monitor and characterize the electrical parameters of the SiC MOSFET. This allows estimations of the health state and predictions of the remaining lifetime prior to its failure. The gate leakage current seems to be a relevant runaway parameter just before failure. This leakage indicates deterioration of the gate structure. This hypothesis has been validated through analysis of scanning electron microscopy pictures, with a focused ion beam cut showing cracks within the polysilicon

9 pagesInternational audienceSilicon carbide (SiC) JFETs are attractive devices, but they might suffer from thermal instability. An analysis shows that two mechanisms could lead to their failure: the loss of gate control, which can easily be avoided, and a thermal runaway caused by the conduction losses. Destructive experimental tests performed on a dedicated system show that the latter mechanism is more severe than initially expected. A low thermal resistance and gate driver equipped with protections systems are thus required to ensure safe operation of the SiC JFETs

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