A Generalized Reaction–Diffusion Model With Explicit H– $\hbox {H}_{2}$ Dynamics for Negative-Bias Temperature-Instability (NBTI) Degradation

In this paper, negative-bias temperature-instability (NBTI) modeling, based on a generalized reaction-diffusion framework, is presented. Unlike the previous models, the release of atomic hydrogen from the Si-H bonds at the Si/oxide interface and its subsequent conversion into molecular H₂ are considered without the (unphysical) assumption of instantaneous transition. The conversion reactions are handled explicitly with finite transition time and numerical solutions that contain both H and H ₂ dynamics are obtained. The conversion reactions result in a distinct time behavior which cannot be predicted from either H- or H₂-only simulations. The results are then explained analytically. The implications of hydrogen conversion dynamics on saturation of NBTI characteristics and device lifetimes are also discussed