NEGF Based Analytical Modeling of Advanced MOSFETs

Identifier:  TDX:2766

Handle: https://hdl.handle.net/20.500.11797/TDX2766

Authors:  Hosenfeld, Fabian

Abstract:
Source-to-drain (SD) tunneling decreases the device performance in MOSFETs falling below the 10 nm channel length. Modeling quantum mechanical effects including SD tunneling has gained more importance specially for compact model developers. The non-equilibrium Green's function (NEGF) has become a state-of-the-art method for nano-scaled device simulation in the past years. In the sense of a multi-scale simulation approach it is necessary to bridge the gap between compact models with their fast and efficient calculation of the device current, and numerical device models which consider quantum effects of nano-scaled devices. In this work, a NEGF based analytical model for nano-scaled double-gate (DG) MOSFETs and Tunneling-FETs is introduced. The model consists of a closed-form potential solution of a classical compact model and a 1D NEGF formalism for calculating the device current, taking into account quantum mechanical effects. The potential calculation omits the iterative coupling and allows the straightforward current calculation. The model is based on a ballistic NEGF approach whereby backscattering effects are considered as second order effect in a closed-form. The accuracy and scalability of the non-iterative DG MOSFET model is inspected in comparison with numerical nanoMOS TCAD data for channel lengths from 6 nm to 30 nm. With the help of this model investigations on short-channel and temperature effects are performed. The results of the analytical Tunneling-FET model are verified with numerical TCAD Sentaurus simulation data.