Statistical variation of NMOSFET hot-carrier lifetime and its impact on digital circuit reliability

The statistical variation of NMOSFET hot-carrier lifetime is studied. The variation in lifetime among spatially separate dies is more significant than the variation within each die. Due to the statistical nature of device hot-carrier lifetime, hot-carrier induced circuit delay degradation in critical paths is a statistical distribution rather than a deterministic parameter. A statistical hot-carrier simulator has been developed to predict the impact that statistical variation of device hot-carrier lifetime has on circuit reliability.