Numerical modeling of a dielectric modulated surrounding-triple-gate germanium-source MOSFET (DM-STGGS-MOSFET)-based biosensor

This paper presents for the first time an analytical model of a dielectric modulated surrounding-triple-gate MOSFET with a germanium source-based biosensor, which shows excellent improvement in sensitivity when compared to a silicon source. The mathematical analysis is based on the center-channel potential which is obtained by solving Poisson's equation in the cylindrical coordinate system using a parabolic approximation. The channel potential profile, threshold voltage, drain current, and subthreshold swing are obtained mathematically. Biosensing performance is investigated for different charged and neutral biomolecules by varying different device metrics including cavity thickness, channel thickness, cavity length, channel doping, and drain voltage. The analytical results are validated and verified with numerical simulations conducted with the ATLAS TCAD simulator and show outstanding agreement with the simulated results.