Compact current modeling of short‐channel multiple gate MOSFETs

Abstract

AbstractWe present a 2D physics based compact model of the double gate (DG) and the gate‐all‐around (GAA) MOSFET, with emphasis on short‐channel devices of nano‐scale dimensions. The compact model is based on a preprocessing routine based on a self‐consistent framework for electrostatics modeling. For sub‐threshold conditions, we assume that the device body is dominated by the solution of the 2D Laplace electrostatics. This assumption is based on the fact that the field strength at the gates emerging from the mobile charge carriers and the doping are much weaker than the fields related to the capacitive coupling between the contacts and the gates. Therefore, we neglect the body charge term in Poisson's equation, converting it to a Laplace equation. Near threshold, the influence of the electronic charge on the electrostatics is taken into account in the framework model in a precise, self‐consistent manner by combining suitable model expressions with the 2D Poisson's equation in the device body. To this end, we consider the self‐consistent potential distributions along the two symmetry axis. Suitable modeling expressions are applied, whose parameters are determined from the boundary conditions and by enforcing self‐consistency using Poisson's equation. The framework and the compact model give excellent results when compared with numerical simulations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)