Sensitivity Analysis of a Polarity-Controlled Tunnel Field-Effect Transistor-based Biosensor

The tunnel field-effect transistor (TFET) is an emerging device for developing highly sensitive biosensors. In this paper, a polarity-controlled TFET (PC-TFET)-based biosensor has been introduced for label-free biomolecule detection. By incorporating the polarity control concept, the biosensor simplifies the fabrication process, minimizes random dopant fluctuations (RDFs), and eliminates the need for high-temperature annealing processes. Additionally, a nano-cavity is created by etching specific areas of the polarity gate's dielectric oxide near the tunneling junction, allowing for better control over the device's tunneling mechanism. The proposed PC-TFET biosensor's sensing capability has been examined for a variety of biomolecules with varying dielectric constants <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(k)$</tex> and charge densities <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\rho)$</tex>. The sensitivity responses have been analyzed in terms of transfer characteristics <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{I}_{\text{DS}}-\mathbf{V}_{\text{CG}})$</tex>, subthreshold swing (SS), ON-OFF current <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{I}_{\text{ON}}/\mathbf{I}_{\text{OFF}})$</tex> ratio and threshold voltage <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{V}_{\text{Th}})$</tex>. The suggested PC-TFET biosensor provides excellent sensitivity for both charged and neutral biomolecules.