Unified Reaction–Diffusion Model for Accurate Prediction of Negative Bias Temperature Instability Effect

In this study, we developed a unified reaction–diffusion (R–D) model for the negative bias temperature instability (NBTI) effect over a wide range of stress times. The newly developed model provides a physics-based uniform solution and overcomes the limitations of the classical R–D models that cannot describe both the short and the long term stress regions simultaneously. In our modeling framework, the chemical reaction between inversion channel carriers and Si–H bonds at the Si/SiO2 interface dominates the short-term NBTI effects at the beginning of the stress application. Then the H2 diffusion into the polycrystalline silicon (poly-Si) gate becomes responsible for long term stress degradation. Finally, the developed R–D model is implemented into the advanced metal oxide semiconductor field effect transistor (MOSFET) model HiSIM to enable accurate circuit-aging simulation. Simulation results for the current degradation and their comparison with measurements verify the achieved high accuracy and the practical applicability of the developed NBTI model.