Performance Assessment of New Dual-Pocket Vertical Heterostructure Tunnel FET-Based Biosensor Considering Steric Hindrance Issue

Abstract

In this paper, a new dual-pocket (DP), dielectric modulated (DM) heterostructured tunnel field-effect transistor (DM-HTFET)-based biosensor has been reported. First, the efficacy of the DP-hetero-TFET (HTFET) has been analyzed by comparing it with other existing TFET structures. Next, a comprehensive assessment of sensitivity between single-pocket (SP) and DP-DM-HTFET biosensors for pocket thickness (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pocket</sub> ), pocket length (Lpocket), pocket doping (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pocket</sub> ), work function of the gate metal, molar fraction of Ge, gate oxide layer, and gate oxide layer thickness (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ox</sub> ) was done. Hence, a nonuniform arrangement of biomolecules inside the cavity simulation has been done using ATLAS device simulation software to validatethe working ability of the proposed sensor. Significant improvement in the sensitivity due to threshold voltage (ON-current) i.e., 26.78% (78.5%), 60.8% (40.4%), 56% (2.2 × 102%), and 40.6% (80.68%) has been observed for the DP-DM-HTFET over SP with the variation of T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pocket</sub> , L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pocket</sub> , N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pocket</sub> , and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ox</sub> , respectively. DP-DM-HTFET-based current mirror circuit has also been demonstrated at the end. Sensitivity evaluation discloses that the DP-DM-HTFET can be a promising candidate for CMOS-based label-free biosensing applications.