MOSFET degradation under DC and RF Fowler-Nordheim stress

Abstract

Fowler-Nordheim (F-N) stress is reported to be one of the most severe wear-out mechanisms for high-frequency MOSFET applications like PAs and RF switches. Previous studies of this degradation process were limited to the DC-static case only and standard empirical models were proposed. In this work a novel general physical model is developed, which correctly describes the ageing of electrical parameters under DC stress. This is made possible by taking into account the hole injection into the gate oxide. Finally this study extends the understanding of F-N degradation to RF regime. In this case a quasi-static sum of the degradation rate is adopted to accurately model and predict the performance worsening; the wear-out shows no frequency dependency in the range up to 4Ghz.