Recovery characteristics of NBTI of pMOSFETs with oxynitride dielectrics under drain bias

In this paper, the recovery characteristics of negative bias temperature instability (NBTI) of pMOSFETs under drain bias were studied. It is observed that, the drain bias not only worsens the NBTI degradation in high |V_ds| region but also suppresses the recovery ratio of NBTI. The time evolutions of recovery show that the drain bias dependent NBTI recovery is mainly related to the fast recovery effect in initial 1s. While in long time scale, the recovery obeys power law dependence on time. A physical model based on donor-type interface traps neutralization at the beginning of recovery is proposed to explain the suppressed recovery ratio under drain bias.