Performance assessment of Si based dual metal double gate vertical TFET biosensor

Abstract

This piece of work highlights the application of dual-metal double-gate VTFET as label free biosensor having enhanced switching ratio, current driving capability and sub-threshold swing and consequently high sensitivity. The use of dual-material namely tunneling gate and auxiliary gate in this device leads to high switching ratio (I_ON/I_OFF) and low sub-threshold swing (SS). In order to observe outcome of this suggested biosensor, various biomolecules dielectric constant have been considered and examined with respect to electric field, energy band diagram, drain current characteristics and sub-threshold potential profile. Neutral biomolecules with a higher dielectric constant exhibits greater drain current sensitivity against biomolecules having lower dielectric constant. Here effect of cavity interface charge on the sensitivity performance of the proposed biosensor device is also verified. This fabrication feasible homo vertical TFET based biosensor gives best sensitivity performance for K = 12, both for the current (5.44 × 10⁵) and transconductance (3.14 × 10⁵) with the minimal sub-threshold swing of 9.9 mV/decade. Silvaco, a commercially accessible TCAD tool is used to investigate the proposed structure.