Modeling, simulation investigation of heterojunction (GaSb/Si) vertical TFET-based dielectric modulated biosensor structure

In this article, an analytical model for dielectric modulated heterojunction (GaSb/Si) vertical tunnel field-feect transistor (DMH-VTFET) based biosensor has been developed and investigated for its biological applications. The presented analytical model incorporates important parameters of biological molecules i.e. dielectric permittivity which provides a generalized view of the physical electrostatics and electrical characteristics of the DMH-VTFET biosensor. Biomolecule immobilization within the cavity causes a change in electrical attributes like surface potential and drain current. It has been analyzed that the various factors (including variations in applied voltages (Vds and Vgs)) results in an impact on the device's electrical characteristics. The results have been validated by comparing the characteristics of the modeling output with simulated outcomes. Furthermore, in this work, the functionality of a label-free biosensor based on a gate overlap DMH-VTFET has also been investigated. The functionality of the DMH-VTFET biosensor is examined with reference to the potential profile, energy band diagram, and drain characteristics for various biomolecules, including Zenin (KC = 7), APTES (KC = 3.57), Gelatin (KC = 12), and Keratin (KC = 10). The substrate layer is divided into eight segments, including source-and drain -depleted segments, to produce the potential model. The pseudo-1-dimensional and 2-dimensional versions of Poisson's equation (PE) are used, respectively, to resolve the potential of each segment. The PEs at the intersegment of various segments are solved using the parabolic approximation process. The Silvaco ATLAS tool is used to recreate the biomolecules using various dielectric constant values for simulation results at technology computer-aided design (TCAD).