Design and sensitivity estimation of linear graded work function gate electrode hetero junction vertical TFET biosensor

This work addresses a novel biosensor design and its surface potential sensitivity analysis to identify various biomolecules. The designed structure integrates the attributes of linear graded work function gate electrode of binary metal alloy and N + pocket of low bandgap SiGe material in double gate-gate stack charge plasma vertical TFET with a single cavity. The dielectric constant modulation corresponding to distinct biomolecules is performed in the cavity to estimate their sensitivity. The dielectric constant modulation leads to variation in energy bands, electric field, and hence in the surface potential of the TFET, the surface potential variation is judged to be resolute sensitivity. Results show that the sensitivity of the neutral biomolecules having higher dielectric constant is observed higher. The surface potential sensitivity of the Gelatin (k = 12) is estimated as 607 which is 5%, 10%, and 48% higher than the sensitivity of Keratin (k = 8), Bacteriophage T7 (k = 6.3), and Glucose Oxidase (k = 3.46) respectively at the cavity length of 43 nm.