Dielectric Modulated InAs Pocket Heterojunction Tunnel FET for Biosensor Applications

This work proposes a dielectric-modulated InAs Pocket Heterojunction Tunnel FET (HJ-TFET) for high-performance biosensing applications. The device features a cavity on the source side and an InAs pocket on the source channel junction, significantly enhancing tunneling current and device sensitivity. The study examines the influence of biomolecule dielectric constants and charge densities on the electrostatics of the device. The results indicate that an increase in the dielectric constant improves the sensitivity, while neutral, positive, or negative biomolecule charges modulate the device response, demonstrating charge-dependent sensitivity variations. Comparative analysis reveals superior performance metrics: threshold voltage sensitivity doubles, drain current sensitivity increases 66 times, and ON-OFF current ratio sensitivity improves fourfold over existing FET-based biosensors. These findings underscore the potential of the InAs pocket HJ-TFET as a robust, high-sensitivity biosensor for detecting biomolecules.