Measurement results of substrate bias dependency on Negative Bias Temperature Instability degradation in a 65 nm process

The transistor size keeps shrinking by Moore's law and timing degradation of the scaled transistors is becoming critical. Recently, the scaling of CMOS technology increases the effect of NBTI (Negative Bias Temperature Instability) in PMOS. NBTI is an important reliability issue for analog as well as digital CMOS circuits. As transistors are scaled refined, the impact of NBTI becomes more critical. This paper deals with relationship between NBTI and the substrate bias. If the substrate bias go a forward, degradation of NBTI is accelerated. We show measurement results of degradation due to NBTI according to the forward and reverse body biases.