An analytical model for read static noise margin including soft oxide breakdown, negative and positive bias temperature instabilities

In this paper, we propose an accurate model for the read static noise margin (SNM). The model includes the effects of soft oxide breakdown (SBD), negative and positive bias temperature instabilities (NBTI and PBTI, respectively). To assess the accuracy of the proposed model, its predictions are compared with those of HSPICE simulations for 32, and 22 nm technologies. The comparison verifies the high accuracy of the model. The results show a maximum error of 4.5% for a wide range of supply voltages. Using this model, the effect of bias temperature instabilities on the aggravation of the read SNM by SBD is also studied. The study shows that both NBTI and PBTI phenomena worsen the effect of SBD on the read SNM by 34%.