A physics based analytical MOSFET model with accurate field dependent mobility

Abstract

A new approach to the modeling of short-channel MOSFETs in the triode region is proposed. A system of equations for an accurate quasi-1-D-formulation of the current transport in MOSFETs is presented. A highly accurate description of the local normal effective field-dependent surface mobility is included. The mobility degradation due to the parallel field is modeled by a hyperbolic formula for P-channel and by Jaggi's expression for N-channel MOSFETs. The mobility models are examined by comparing with several experimental data. The system includes a precise modeling of the inversion layer charge and surface potential, and it is valid in both weak and strong inversion. Using novel approaches an approximate solution in the triode region is derived analytically. The obtained expressions for the current are explicit. An error analysis of the analytical current models is carried out by comparing with a numerical solution of the starting quasi-1-D-formulation. As a result of the error analysis the simplest final expression for the drain current is proposed. Some further extensions of the model are noted.