Performance Assessment and Optimization of Vertical Nanowire TFET for Biosensor Application

Abstract

This paper reports the performance assessment of vertical silicon nanowire TFET (V-siNWTFET) design for biosensor applications using dielectric-modulation and gate underlap technique. The sensitivity of the V-siNWTFET is recognizing by immobilizing the different biological molecules such as lipids, biotin, uricase, protein, Gox, streptavidin, uriease, zein etc. in the cavity region which is created under the gate electrode and source oxide. The performance analysis is observed by varying the relative permittivity of the different biomolecules and analyzes the parametric variation both for neutral and charged biomolecules. The sensitivity of the biosensor has been detecting in the terms of drain current (ID), threshold voltage (VTH), subthreshold slope (SS), transconductance (gm), and ION/IOFF ratio. The proposed device structure has capable to reduce the leakage currents and high sensitivity biosensor design in the nanoscale regimes. The obtained best optimum parameters of the proposed devices are ION (1.37E−08 A/µm), IOFF (9.44E−19 A/µm), SS (29.97 mV/dec) and ION/IOFF (4.29E + 10) ratio with gate work-function (ϕgate = 4.8 eV) and uniformly doped (1 × 10–19 cm−3) silicon nanowire at drain to source voltage (VDS = 1.0 V). The higher sensitivity of the proposed V-siNWTFET for Biosensor is observed for Zein biomolecules (K = 5).