Synopsys, Inc.
Local band-to-band-tunneling model for TCAD simulation

Abstract:

An improved local modeling function for estimating band-to-band tunneling currents R.sub.BBT in nanodevices and other low-voltage circuit elements during TCAD simulation, the model being represented by the equation: .times..times..times..sigma..function..times. ##EQU00001## where terms B, F, F.sub.0 and .sigma. correspond to conventional terms used in Hurkx-based equations, and the term g is an exponential factor determined by the equation: ##EQU00002## where the term F.sub.1 is the built-in electric field at a selected cell/point determined by the equation: .function..about..times..times..times..times..times..times. ##EQU00003## where {tilde over (F)}.sub.1 is the built-in electric field at zero bias, q is fundamental electronic charge, C is a fitting parameter, E.sub.g is bandgap, N.sub.net is doping concentration, and E is dielectric constant. At low applied fields (F.about.F.sub.0) the factor g biases the improved model toward the zero-field/zero-current origin in a way that closely matches non-local model results. At higher applied fields the factor g has less influence and the model is controlled by the conventional terms.