Modeling of junctionless based dielectric modulated vertical TFET biosensor

Abstract

This research article focuses on using a junctionless-based dielectric modulated vertical Tunnel FET (VTFET-DM-JL) as a biosensor. The objective is to detect biomolecules without the need for labeling, using electrical signals by modulating the dielectric constant. The JLFET, which is a device without any doping gradient or junction, serves as the structural foundation for this research. To understand the behavior of the structure, a potential model is created in this research which involves solving the Poisson equations (PE) under various boundary conditions. In addition, the incorporation of a high-K gate oxide improves the reliability of the device, particularly in terms of low power consumption. The paper explores the impact of dielectric constant values ranges from 1 to 12 by calculating figure of merit (FOM) values, including linearity, sensitivity, and noise assessment. As an example, Gelatin with a dielectric constant value of 12 exhibits a drain current sensitivity of 6.7 × 108, which is 9 % higher than apomyoglobin (κ = 8.1), 12 % higher than Bacteriophage-T7 (κ = 6.4), and 46 % higher than APTES (κ = 3.57) sensitivity, at a cavity length of 30 nm. Additionally, various FOMs, including linearity, sensitivity, and noise characteristics, are computed for the device across the dielectric constant range of 1–12. The simulated results obtained using the widely available Silvaco TCAD tool is compared with the modeled outcomes. A comprehensive assessment of the FOM standards establishes the promising nature of the proposed VTFET-DM-JL structure in terms of linearity and sensitivity.