Sensitivity Analysis of a Novel Negative Capacitance FinFET for Label-Free Biosensing

Abstract

We propose and analyze a dielectric modulated (DM) negative capacitance (NC) fin-field effect transistor (FinFET) based biosensor for efficient and label-free detection of biomolecular entities. For the first time, the NC effect on bio-sensing owing to the presence of a dielectric-ferroelectric gate oxide stack is investigated. First, capability of the NC-FinFET is compared with the baseline FinFET as percentage variation in electrical parameters. Also, the sensing capability of the proposed device is examined with a wide variety of biomolecules with varying dielectric constants. Inclusion of the NC effect in the biosensor exhibits very high sensitivity in terms of the electrical figures of merit (FoMs) such as threshold voltage, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I_{\mathrm{\scriptscriptstyle ON}}/{I}_{\mathrm{\scriptscriptstyle OFF}}$ </tex-math></inline-formula> -ratio, output conductance, and intrinsic gain with rapid response because of the steep subthreshold value. The use of raised source drain (RSD) architecture allows more cavity space to the biomolecules and, hence, increases the sensitivity and selectivity of the biosensor. All the device simulations are performed in a 3-D Sentaurus TCAD environment using well-calibrated structure. To establish a benchmark, the sensitivity of the proposed biosensor is also compared with the published literature in order to determine its effectiveness. The results of this study can establish NC-FinFET as a viable candidate for label-free DM biosensor applications.