Analytical Physics-Based Modeling of Electron Channel Density in Nanosheet and Nanowire FETs

TL;DR

This paper introduces a physics-based analytical model for calculating the electron channel density in nanosheet and nanowire FETs, covering subthreshold and above threshold regions with explicit formulas.

Contribution

It presents a unified analytical approach considering electrostatics and potential balance, including new definitions of threshold voltage for nanoscale FETs.

Findings

Explicit analytical expressions for channel charge density

Unified model applicable to various FET geometries

Discussion of threshold voltage definitions

Abstract

We propose a general physics-based approach for an accurate analytical calculation of the channel charge density in field-effect transistors as functions of the external gate biases. This approach is based on a consistent consideration of basic electrostatic equation as a balance of electric and chemical potentials which allows us to obtain in a unified way the explicit analytic expressions continuously de-scribing the subthreshold and above threshold regions in nanosheet (symmetric and asymmetric) and nanowire FETs. Two conceptually different definitions of phenomenological threshold voltage are consistently introduced and discussed.