Preconditioning for Accurate Threshold Voltage Extraction of SiC MOSFETs after AC Bias Temperature Instability in Reliability Tests

Due to their significant reliability issues, SiC MOS-FETs have faced limitations in their widespread adoption. One of the critical reliability concerns is related to the gate oxide layer of SiC MOSFETs, known as Bias Temperature Instability (BTI). This phenomenon describes the drift in the threshold voltage of SiC MOSFETs under gate bias and high-temperature. This reliability issue poses challenges for the design, manufacturing, and application of SiC MOSFETs. To accurately measure the drift, necessary preconditioning procedures and carefully designed test sequences are crucial. In this paper, the drift in the threshold voltage of SiC MOSFETs under AC gate stress was discussed through accelerated degradation tests, and the significance of preconditioning operation before analyzing the results was emphasized.