Design and Analysis of 18 nm Multichannel FinFET as Biosensor for Detection of Biological Species

This work presents a design of high sensitivity 18 nm multichannel FinFET as a biosensing element used to detect nano bio-species. The effect of different types of biomolecules such as Keratin, Gluten, Zein and Biotin on the performance parameters of the 18 nm multichannel FinFET 3D device is observed. The device sensitivity is analysed by introducing different dielectric materials over the exposed channel region around the gate. The suggested device gives ON and OFF-state current of the order ~10 −4 A/um and ~ 10 −16 A/um respectively and I ON /I OFF ratio up to 10. 12 Deflection in V th (ΔV th ) was observed to be 0.54 V and 0.23 V for values of dielectric constant (K) 10 and 1 respectively. The subthreshold performance and sensitivity are examined for the proposed FinFET. The sensitivity of transistor is evaluated by exposing the channel region for different neutral and charged bio molecules. Dielectric constant and exposed channel length is varied to analyse the device sensitivity towards biomolecules. A sharp variation in OFF current and ON/OFF current ratio is observed with different neutral, positively and negatively charged bio species. The FinFET-based biosensor is highly sensitive to nano and micro level bio-molecules which is responsible for the variation in dielectric constant of the exposed channel region along with concentration and type of charge present on bio-molecules. The proposed FinFET as biosensor is calibrated in terms of drain current with respect to variation in dielectric parameter, magnitude and type of charge present on biomolecules.