Overcoming Biomolecule Location-Dependent Sensitivity Degradation Through Point and Line Tunneling in Dielectric Modulated Biosensors

Abstract

In this paper, we report on the utility of pocket tunnel field-effect transistors (TFETs) for use as dielectric-modulated biosensor. It is shown that incorporation of a pocket doping in the source facilitates lateral as well as vertical tunneling, which allows biomolecules located at various positions within the cavity to cause a detectable shift in current-voltage characteristics. Considering realistic cases pertaining to varied locations of biomolecules within the cavity and low fill-in (50%) factor, pocket TFET shows enhanced sensitivity over conventional TFET, which can be further improved by lowering the pocket doping. Sensitivity of a pocket TFET maintains detectable values over a wide range of biomolecule locations within the cavity, thereby showing potential for next generation transistor-based biosensor.