A Novel T-Shape Channel With an Inverted-T Nano-Cavity Label-Free Detection Using Si:HfO<sub>2</sub> Ferroelectric DGDM-JLTFET as a Biosensor—A Simulation Study
Rapolu Anil Kumar, K. Girija Sravani, Girish Wadhwa, K. Srinivasa Rao
Abstract
In this article, we present and simulate a very sensitive label-free biosensor that uses Si:HfO2 ferroelectric (FE) junction less tunnel field-effect transistor (FE-JL-TFET) charge/dielectric modulation. For the first time negative capacitance (NC) behavior is made possible by the FE gate stacking of Si-doped HfO2 in the dual inverted-T cavity with T-shaped channel is used in the biosensor design. Using a sacrificial etching approach, two cavities are formed in the gate-source underlap areas to detect biomolecules such as lipid (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K}= {3}$ </tex-math></inline-formula>), carbohydrates (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K} =5$ </tex-math></inline-formula>), plant protein zein (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K} = 7$ </tex-math></inline-formula>), amino acids (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K} =12$ </tex-math></inline-formula>), and MDA-MB-231 (breast cancer cell, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K} = 22$ </tex-math></inline-formula>). For both charged and neutral biomolecules, the biosensor has shown increased sensitivity. The biomolecules that are neutrally, positively, and negatively charged have maximal values of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} _{\text {on}}$ </tex-math></inline-formula>/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} _{\text {off}}$ </tex-math></inline-formula> ratio that reach as high as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.65\times 10^{{10}}$ </tex-math></inline-formula>, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.24\times 10^{{10}}$ </tex-math></inline-formula>, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$9.47\times 10^{{10}}$ </tex-math></inline-formula>, respectively. It has been noted that the proposed device sensing performance can be greatly enhanced by optimizing the cavity height and length. For neutral, negative, and positive charged biomolecules, the proposed biosensor sensitivity has been greatly increased to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8.61\times 10^{{4}}$ </tex-math></inline-formula>, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.93\times 10^{{3}}$ </tex-math></inline-formula>, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.05\times 10^{{5}}$ </tex-math></inline-formula>, respectively. It has shown better sensitivity when compared with other advanced biosensors.