Modeling and Performance Analysis of a Split-Gate T-Shape Channel DM DPDG-TFET Label-Free Biosensor

Abstract

This article proposes, for the first time, a split-gate T-shape channel dielectrically modulated (DM) double-gate TFET (DGTFET) with a drain pocket (DP). This device can be used as a label-free biosensor. The analytical model for DM DPDG-TFET has been developed and it has been validated against commercial simulation software (Silvaco TCAD). This article intends to focus both on the sensitivity of the biosensor and its performance as a tunnel field-effect transistor (TFET) device. This has been accomplished by improvisations in the channel shape. The performance of the device has thoroughly been investigated in terms of threshold voltage, subthreshold slope, ON current, and OFF current. Due to the novel design, the proposed TFET possesses higher sensitivity, higher <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{ {\text{ON}}}/{I}_{ {\text{OFF}}}$ </tex-math></inline-formula> current ratio, and lower subthreshold slope. The inclusion of DP at the drain–channel junction proves to be a successful way to remove the ambipolarity completely. The high ON current without any ambipolarity has been achieved by optimizing the DP length and its doping concentration. The proposed T-shape DM DPDGTFET proves itself to be superior to several reported devices in terms of both biosensor as well as field-effect transistor (FET) device. The presence and absence of charge of various biomolecules are taken into consideration for evaluation of device sensitivity as a label-free biosensor.