Establishment of Degradation Model and Transfer Model for P-channel Power MOSFETs Under Negative Bias Temperature Stress

Negative Bias Temperature Instability (NBTI) is the main reason for the degradation of gate oxide in P-channel power MOSFETs. Affected by long-term negative bias gate voltage and high temperature, the threshold voltage of power MOSFETs drifts, which in turn affects the performance of the device. Based on the analysis of NBTI failure mechanism, this paper conducted accelerated degradation test on six different types of P-channel power MOSFETs. Secondly, the Iterative Reweighted Least Square (IRLS) method was applied to establish a threshold voltage drift's degradation model, which can accurately describe actual degradation data. In addition, a transfer model was established using multiple linear regression theory to approximately describe the relationship between the fitting parameters of degradation model and power MOSFETs' process parameters, providing a new approach for the fast reliability assessment of P-channel power MOSFETs.