Design and Analysis of Dual-Metal-Gate Double-Cavity Charge-Plasma-TFET as a Label Free Biosensor
Mahalaxmi, Bibhudendra Acharya, Guru Prasad Mishra
Abstract
In this paper, the bipolar nature of tunnel field effect transistor (TFET) has been utilized for the first time for the identification of biomolecules. Charge plasma concept has been employed to achieve simpler process of fabrication, lower cost and to overcome random dopant fluctuation. The focus of this work is to utilize both ON and ambipolar state of dual metal gate double cavity charge plasma TFET (DMG-DC-CPTFET) biosensor for sensing the biomolecules. Consideration of cavities at both tunneling junctions, it is possible to sense different kinds of biomolecules simultaneously. Gate workfunction engineering has been employed to improve sensitivity and to minimize the OFF state current of the proposed biosensor. High-k gate dielectric is used to achieve maximum ON current. The variation in electrical characteristics like energy band, surface potential and the electric field resulting from the presence of charged and neutral biomolecules in the cavities has been studied. The proposed model offers maximum sensitivity of 2.88 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> (2.88 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> %) under ON state and 1.37 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> (1.37 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> %) under ambipolar state.