Design of VTFET-Based Biosensor Utilizing Ambipolar Current in Detection Mechanism

This work presents a vertical TFET -based biomolecule biosensor that utilizes ambipolar current of the VTFE T as a parameter for sensitivity measurement. Unlike conventional TFET biosensors, which capture biomolecules at the source side, the proposed biosensor is designed to capture biomolecules at the drain side. Additionally, the biomolecule receptors are positioned on an open sensing surface to capture the biomolecules as opposed to the enclosed cavity used in FET- based biosensors. The highest ambipolar current sensitivity of 4.18 x 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> is recorded in this work. Biomolecules vary in size and orientation and may create different biomolecule layer thicknesses after being attached to the receptors. A study is done to find the effect of the biomolecule layer thickness on the sensitivity of the biosensor. It is seen that sensitivity increases with the increase of the biomolecule layer thickness. A 10 nm thickness of the biomolecule layer produces the highest sensitivity in this work.