Analytical Modeling of Short-Channel Effects in MFIS Negative-Capacitance FET Including Quantum Confinement Effects
Nilesh Pandey, Yogesh Singh Chauhan
Abstract
An analytical 2-D model of double-gate metal-ferroelectric-insulator-semiconductor-negative-capacitance FET (MFIS-NCFET), using Green's function approach, in the subthreshold region, is presented in this article. The explicit solution of coupled 2-D Landau-Devonshire and Poisson equations is analytically derived. Subsequently, an analytical and explicit model of subthreshold slope is developed from potential functions. The developed model includes quantum-mechanical effects, which considers not only geometrical confinements but also electrical confinements. The analytical solution of a 2-D nonhomogeneous Poisson equation coupled with the 1-D Schrödinger equation is used to obtain the potential function in the channel. The impact of the ferroelectric thickness (t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fe</sub> ) on quantum confinement is also studied. We find that larger tfe reduces the quantum confinement effect. Therefore, as t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fe</sub> increases, threshold voltage roll-off with the variation in Si-body thickness decreases.