Dielectric modulated TFET on SELBOX substrate as a label-free biosensor applications: analytical modeling study and sensitivity analysis

Abstract

The manuscript proposes a ferroelectric heterojunction TFET (BG-FE-HJ-STFET) on SELBOX substrates with a back gate to create an ultra-sensitive label-free biosensor with dielectric modulation for the detection of neutral and charged biomolecules. Within the proposed device, four cavities have been carved out for the biomolecules’ immobilization under the front and rear gate dielectrics. By using a ferroelectric (FE) material as a gate stack, the low gate voltage is increased to be more effective by causing a negative capacitance phenomenon. The response of the proposed biosensor to four impartial biomolecules with different dielectric constants: protein (k = 8), biotin (k = 2.63), 3-Aminopropyl-triethoxysilane (APTES) (k = 3.57), and streptavidin (k = 0.1) has been investigated. Deoxyribonucleic acid (DNA), a charged biomolecule, is also examined for the dielectric constant of k = 6 concerning both charge (negative and positive) densities. The device is simulated with the commercially available SILVACO ATLASTM TCAD tool. The performance analysis relies on several figures of merit (FOMs) such as DC/RF and sensitivity (including drain current, I ON /I OFF ratio, and subthreshold swing) for both neutral and charged biomolecules. The optimized cavity structure demonstrates a notable sensitivity in drain current (2.7 × 108) and a significant I ON /I OFF sensitivity (1.42 × 1011). One of the main problems with current biosensors is the difficulty and expense of production in the nanoscale realm. © 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.