Design and Simulation of Silicon-on-Insulator Based Dielectric-Modulated Field Effect Transistor for Biosensing Applications

Abstract

In this paper, a detailed analysis of the electrostatic effects on the threshold voltage of an Silicon-on-Insulator(SOI)-based dielectric-modulated field effect transistor (DMFET) label-free biosensor has been done. The simulations for SOI DMFET biosensor was performed using Silvaco® TCAD ™ tool. The concentration of biomolecules in the analyte introduces changes in the dielectric constant and surface charges, and a parametric study is performed to study the device sensitivity. To study these effects, modulation of dielectric constant and the charge interaction was performed which leads to a shift in the value of threshold voltage and transconductance of the transistor. The analysis has been performed on SOI based technology to study the effect of buried oxide thickness, active layer thickness and substrate voltage. It was observed that they significantly affect the electrical characteristics of DMFET.