Design and Analysis of Junctionless Based Symmetric Nanogap-Embedded TFET Biosensor

In the present paper, symmetrical configuration of dual material double gate dielectric modulated junctionless TFET (DM DG JLTFET) for biosensor applications is explored. The JLTFET consists of Si material with an intensely doped n-type substrate. In this work, the JLTFET utilizes the dielectric modulation method which aids the bio-transistor to recognize neutral and charged analytes (biomolecules). A double metal gate structure is designed by employing two dissimilar metal gate electrodes to reduce short channel impact on device characteristics. The proposed device includes a nanogap region (cavity) which is framed for biomolecules to immobilize. Surface potential and their sensitivity are examined for neutral and charged-neutral analytes. The effects of structure parameters such as nanogap region length and fill-in factor have been analyzed through simulation. The paper examines the behavior of DM DG JLTFET for biological molecules sensing via change in relative permittivity and charge density. The proposed device shows noticeable sensitivity results for charged biomolecules (especially for positively charged analytes). The present work has analyzed the different parameters affecting the sensitivity of the biosensor which includes structural geometric variations like change in cavity length, cavity thickness and fill-in factor. 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 3.75 x 10(3) which is 45%, 55%, and 135% higher than the sensitivity of Keratin (k = 7), Bacteriophage T7 (k = 6), and Glucose Oxidase (k = 3) respectively at the cavity length of 7 nm.