NBTI in p-channel power U-MOSFETs: Understanding the degradation and the recovery mechanisms

In this paper, we present an analysis of the degradation mechanisms in p-channel power U-MOSFETs due to Negative Bias Temperature Instability (NBTI). In particular, we study the influence of NBTI on threshold voltage and trans-conductance, which are the main figures of merit affected by charges trapping in the bulk oxide and by an interface defects generation. At the end of the stress, a recovery phase is implemented in order to monitor permanent and recoverable degradation. Moreover, we investigate the influence of the overall channel area on the threshold voltage degradation and on device lifetime.