On the PBTI degradation of pMOSFETs and its impact on IC lifetime

Based on our investigations we are able to conclude: PBTI at pMOSFETs with SiON gate oxide leads to parameter degradation in the same direction as NBTI with a Power-Law time dependence. We recorded a very fast recovery characteristic comparable to NBTI. Since the damage occurs mainly at the interface on the other side of the gate oxide there is no or only a weak correlation in the amount of parameter degradation between NBTI and PBTI degradation. When the stress modes are cascaded as during product operation, we could obtain coexisting parallel trapping/de-trapping of holes and electrons. As a consequence the degradation and recovery cannot longer be explained by one single trapping mechanism. This challenges extrapolations and lifetime predictions. The silver bullet is if such stress operation conditions can be avoided in the product design by 'Design for Reliability' (DfR).