Nanocavity-Modulated Gate-Engineered InGaN Dopingless TFET: A Case Study for Breast Cancer Biosensing

چکیده

This work presents a nanocavity-modulated gate-engineered InGaN dopingless tunnel field-effect transistor (TFET) as a case study for breast cancer biosensing. The proposed device combines charge-plasma source/drain formation with a retained tunneling gate and a dielectric-sensitive nanocavity positioned beneath the control-gate region. The cavity is intended to accommodate an immobilized recognition layer, captured breast-cancer-associated biomarkers, and the surrounding local fluid, while different biological conditions are represented through effective dielectric signatures rather than intact cells. Device behavior is investigated using two-dimensional TCAD simulations with a nonlocal band-to-band tunneling model and relevant carrier transport and recombination mechanisms. The sensing principle relies on dielectric modulation of the local electrostatic coupling, which alters the energy-band profile, tunneling barrier, carrier concentration, and drain-current response. The simulated results show clear separation between the air-filled reference state, the non-tumorigenic reference condition, and malignant-associated dielectric conditions. Key electrical indicators, including ON/OFF current ratio, average subthreshold swing, maximum transconductance, and ON-state current, exhibit strong and systematic variation with cavity permittivity. The proposed architecture therefore offers a promising route toward label-free, low-power, and electrically distinguishable biosensing using an InGaN tunneling platform.