Analytical Exploration and Simulation of Dual-Material Gate Macaroni Channel MOSFET biosensor using dielectric-modulation technique

Abstract

The paper presents extensive analytical modeling and simulation of a novel Dual-Material Gate Macaroni-Channel MOSFET to act as a biosensor for detection of neutral as well as charged biomolecules using dielectric modulation approach. Dielectric modulation in a MOSFET device is the alteration in the dielectric constant in the gate dielectric region of the device. Presence of biomolecules (in a nanogap etched under the gate of the projected device) having different dielectric constants impact the gate capacitance that in turn affects the device features such as potential, threshold voltage, drain current which undergo considerable shift in presence of biomolecules. Detailed Sensitivity analysis based on threshold voltage shift for different types of biomolecule allows suitable detection of biomolecule type. Suitable selection of device outer radius allows significant suppression of some major Short channel effects such as threshold voltage reduction, reduced subthreshold swing enabling superior device performance. Finally, comparative sensitivity analysis of the proposed device with its full channel Cylindrical Gate-all-around counterpart having same channel thickness exhibits better sensitivity capability of the proposed device for both neutral and charged biomolecule. Analytical results are substantiated using Atlas simulation outputs.