A Dynamic Current Model for MFIS Negative Capacitance Transistors

A dynamic current model for the double gate negative capacitance field-effect transistor (NCFET) of the metal-ferroelectric-insulator-semiconductor (MFIS) structure is presented in this work. With a damping parameter ρ in the Landau-Khalatnikov (LK) theory for general ferroelectric (FE) materials, the gate control equation of NCFET is intrinsically dynamic which is solved directly as a basis of NCFET modeling. With the time-dependent charge densities at the source and drain sides, a dynamic current model is formulated analytically for the first time, considering the dynamic terms in a self-consistent way. The model has been verified with numerical TCAD simulations. It accurately reproduces the static negative capacitance (NC) effect in enhancing the driving current, as well as the dynamic NC effect, in the conduction delay and hysteresis for a wide range of NCFET parameters. The dynamic model after implementations is successfully applied to circuit simulations such as ring oscillators without convergence issues.