Dielectric modulation-based biomolecule detection using III-V vertical source-all-around tunnel FET

We present a dielectric modulation-based label-free biosensor utilizing a GaAsSb/GaSb heterojunction in source-all-around vertical tunnel FET (TFET) configuration. The TFET, enhanced with a heavily doped source pocket and a metal core, exhibits improved gate control, current ratio, and subthreshold swing (SS). This novel design is evaluated for its sensitivity to biomolecules with various dielectric constants (5.5, 7.5, 10, and 12) through extensive TCAD simulations. Sensitivity analysis is conducted for different nanogaps, fill factors, and biomolecule charges (neutral, positive, and negative). The wide tunneling area provided by this source-allaround structure significantly increases the biomolecule capture area, resulting in superior sensitivity compared to other devices. Thus, the proposed TFET demonstrates excellent potential for diverse biomolecule detection applications.