DESIGN AND SIMULATION OF HETERO-JUNCTION TUNNEL FET FOR BIOSENSING APPLICATION

Abstract

Tunnel Field Effect Transistors (TFETs) have emerged as promising alternatives for low-power applications, offering advantages like low power dissipation, reduced leakage current, and subthreshold swing below 60 mV/dec. TFETs operate on the principle of band-to-band tunneling (BTBT), and though they have lower Ion cur- rents, structural modifications can improve performance. Various TFET architectures, including heterojunction and dual-gate designs, have been developed to enhance the Ion/Ioff current ratio and lower threshold voltage. Different TFET device reviews con- clude that TFET biosensors based on P-N-P-N provide insight into electrical character- istics, although detailed sensitivity analyzes remain underexplored. TFET as biosen- sor give high sensitivity in impact ionization-based MOS transistor biosensors but did not address the effects of varying biomolecule concentrations TFET-based biosensors, leveraging their low power consumption and high sensitivity, outperform traditional FET-based biosensors, addressing limitations like short-channel effects and power dis- sipation. This review explores TFET structures, performance parameters, and their ap- plication in biosensing, highlighting sensitivity factors and design optimizations. we introduce a sensor based on a dielectric-modulated InAs Pocket Hetero Junction TFET (HJ-TFET), designed for power-efficient, label-free bio-molecule detection applica- tions. The results demonstrate enhanced sensitivity to two distinct effects—dielectric constant and bio-molecule charge—compared to a FET-based biosensor. Key perfor- mance metrics, such as threshold voltage sensitivity, are also improved (∆V th), Ion/Ioff current sensitivity, and drain current sensitivity (SId) are calculated. We also present a comparative analysis demonstrating that this sensor is superior to others. The study examines neutral, positively charged, and negatively charged bio-molecules across var- ious dielectric constants at the interface between the gate and channel.