A Simple Charge and Capacitance Compact Model for Asymmetric III-V DGFETs Using CCDA

Abstract

In this paper, we have proposed a simple, computationally efficient and physic-based compact model for III-V double gate field effect transistors (DGFETs) including gate insulator thickness asymmetry. The semiconductor charge and the gate capacitance are calculated using the recently proposed constant charge density approximation (CCDA). The CCDA approximation eliminates the need of knowing the exact wavefunction and thus provides an analytically simple way to model the DGFET electrostatics. The CCDA approximation assumes a constant charge centroid which is a limitation of this methodology. To address this issue, a physics-based charge centroid correction is also presented in this work. The proposed model (with charge centroid correction) is mathematically simple, scalable to any (a) (b) number of sub-bands and accurate for a wide range of gate voltages.