Sensitivity and reliability assessment of pocket doped NCFET based dielectrically modulated biosensor considering steric hindrance effects

Abstract

Abstract The paper explores the biosensing investigation of Highly Doped Double Pocket Double Gate Negative Capacitance Field Effect Transistor (HDDP-DG-NCFET) for the potent and label free detection of bio-molecules. The biosensing figure of merits (FoMs) such as threshold voltage sensitivity (∆Vth), ON–OFF current ratio sensitivity (∆ION/IOFF), intrinsic gain, drain current sensitivity (SId) and transconductance (gm) are computed for HDDP-DG-NCFET based biosensor. The study considers neutral, negatively (–NBio) and positively (+NBio) charged biomolecules at different dielectric materials such as air (ε k = 1), 3-aminopropyl-triethoxysilane (APTES) (ε k = 3.57), zein (ε k = 5), keratin (ε k = 8) and gelatin (ε k = 12) at the immobilization layer. Additionally, an extensive analysis of a partially filled nanocavity triggered by steric hindrance has been presented to encompass the real-world situation and to comprehend the non-ideal behavior of biosensor. Various scenarios of partly occupied nano-cavities as well as asymmetric probe insertion have been accounted. The significant biosensing metrics such as ∆Vth, ∆ION/IOFF and SId are calculated and have ensuing values as 188 mV, 3 × 104 and 138, respectively. In addition, the maximum SID for fully filled nano-cavities (FF = 100%) in the existence of +NBio and -NBio (±5 × 1012) are 194 and 170, respectively for HDDP-DG-NCFET based biosensor. Finally, to illustrate the outstanding sensitivity of the proposed biosensor, various sensitivity metrics of the HDDP-DG-NCFET are compared to the sensitivities of cutting-edge biosensors which demonstrate HDDP-DG-NCFET as a potential contender for label free biosensor applications.