14 nm Negative Capacitance FinFET Design as Biosensor

Sensors play an important role in disease prediction and patient care by monitoring the concentration of biomolecules, viruses, and charged particles in the human body. The changes in concentration and charge of biomolecules are predicted by efficient biosensors, viz., BioFET, by measuring the changes in electrical parameters. The high performance and better gate control of FinFET make it a suitable candidate for biosensing by systematically calibrating changes in electrical parameters, including dielectric variation, to determine changes in drain current (Id). In this work, a 14 nm FinFET-based biosensor has been designed by adding nanogap cavity regions near the side gates. The performance of the proposed biosensor is analysed by evaluating ∆Id (A/µm) variations, threshold voltage (Vth) shift, electric field, and channel potential in the presence of biomolecules and cavity regions. The biosensor sensitivity is analysed over a specific range of dielectric constants near the k-value of the protein in the human body using the dielectric modulation technique. A single cell of the proposed NC-FinFET has demonstrated a sensitivity of up to 18.4%. Multiple blocks of NC-FinFETs can be explored to further increase the sensitivity of the biosensor array. All design and simulation are performed in a 3D Visual TCAD tool from Cogenda. The paper also demonstrates the predicted fabrication steps for the proposed NC-FinFET as a biosensor.