A physically based analytical modeling of threshold voltage control for fully-depleted SOI double gate NMOS-PMOS Flexible-FET

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 180nmFlexible-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.