A Complete Condition Monitoring Method for SiC MOSFETs with BTI Recovery Function

Real-time condition monitoring (CM) of various degradation modes is an effective way to improve reliability of Silicon carbide (SiC) MOSFETs. Currently, gate-oxide and bond wire degradation are the focus of attention. However, it is a challenge to monitor these two degradation modes independently. In this article, a complete degradation monitoring method for SiC MOSFETs based on short-circuit (SC) conditions is proposed, which can separate different degradation modes and has BTI recovery function. By triggering one cycle of SC condition, the gate-oxide degradation can be monitored by detecting the peak value of SC current. Then, the voltage ringing between Kelvin source and power source <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(v_{\mathrm{K}\mathrm{S}-\mathrm{S}})$</tex> can reflect bond wire degradation. In order to decouple the effect of gate-oxide degradation, the voltage ringing of the circuit parasitic inductance <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(v_{\text{EQU}})$</tex> is introduced, and the ratio of their peak values is taken as bond wire degradation precursor. Finally, the effectiveness of the proposed method is verified through experiments.