Investigation of BTI-induced Threshold Voltage Shift for Power MOSFETs during Switching Operation

The threshold voltage (Vth) shift caused by bias temperature instability (BTI) in power MOSFETs is crucial for ensuring the reliability of power conversion circuits. In this paper, a novel BTI-induced threshold voltage characterization method is presented. As opposed to existing methods in which static voltage input is applied, this method takes into account actual switching operations. Through the experiments using commercially available SiC MOSFETs, the Vth shift is evaluated and the physical mechanism of BTI is discussed on the basis of the measured Vth data.