Measurement of BTI-induced Threshold Voltage Shift for Power MOSFETs under Switching Operation

While silicon carbide (SiC) MOSFETs can tolerate high-voltage and high-temperature operations with low power loss, long-term reliability of SiC devices is of a concern due to the threshold voltage shift caused by bias temperature instability (BTI). Although the industry-standard BTI characterization method can measure long-term threshold voltage fluctuation, it is hard to quantify the fluctuation under the actual switching operation. In this paper, we propose a long-term BTI characterization method that reflects a realistic switching operation of power devices. We demonstrate the effectiveness of the proposed method using a commercial SiC MOSFET and then discuss the suitable model to represent BTI on the basis of the measurement data.