A Physically Based Analytical Modeling of Threshold Voltage Control for Fully-Depleted SOI Double Gate NMOS-PMOS Flexible-FET

TL;DR

This paper presents an explicit analytical model for the threshold voltage variation in Fully-Depleted SOI Double Gate NMOS-PMOS Flexible-FETs, validated against experimental data and simulations, aiding device design optimization.

Contribution

It introduces a novel explicit analytical equation for threshold voltage control in Flexible-FETs, incorporating 2-D Poisson's equation and Young's approximation, with validation against experimental and simulation results.

Findings

Excellent match with experimental data for 180nm Flexible-FETs

Threshold voltage varies with oxide and silicon thickness, doping levels

Model provides qualitative agreement with SILVACO simulations

Abstract

In this work, we propose an explicit analytical equation to show the variation of top gate threshold voltage with respect to the JFET bottom gate voltage for a Flexible Threshold Voltage Field Effect Transistor (Flexible-FET) by solving 2-D Poisson's equation with appropriate boundary conditions, incorporating Young's parabolic approximation. The proposed model illustrates excellent match with the experimental results for both n-channel and p-channel 180nm Flexible-FETs. Threshold voltage variation with several important device parameters (oxide and silicon channel thickness, doping concentration) is observed which yields qualitative matching with results obtained from SILVACO simulations.