Exploring the Potential of Dielectric Modulated SOI Junctionless FinFETs for Label-Free Biosensing

This research presents a biosensor based on a dielectrically modulated (DM) silicon on insulator (SOI) junctionless fin-shaped field-effect transistor (FinFET) (DM-SOI-JL-FinFET) for the detection of biomolecules. This biosensor is integrated with a label free detection of neutral biomolecules such as biotin (k = 2.53), APTES (k = 3.57), ferro-cyt C (k = 4.7), bacteriophages (k = 6.3), and keratin (k = 8). By etching the gate oxide, a nanocavity with a thickness of 5 nm and a height of 35 nm is created for immobilized biomolecules. The presence of biomolecules is determined by observing variations in the dielectric constant. Various important parameters including threshold voltage, the ratio of on-state and off-state current (I_ON/I_OFF) sensitivity, drain current, transconductance, and surface potential are thoroughly investigated for different biomolecules with a function of dielectric constant, fin height, and fin width. The study demonstrates a threshold voltage sensitivity (S_v) of 0.1552 (biotin, k = 2.53) and 0.5628 (keratin, k = 8), as well as an I_ON/I_OFF current sensitivity (S_I) of 1.1609 (biotin, k = 2.53) and 3.9774 (keratin, k = 8) for the simulated structure.