Sensitivity Analysis of Biomolecule Nanocavity Immobilization in a Dielectric Modulated Triple-Hybrid Metal Gate-All-Around Junctionless NWFET Biosensor for Detecting Various Diseases

Abstract

In this paper, a novel biomolecule nanocavity immobilization in a dielectric modulated triple-hybrid metal gate-all-around (THM-GAA) junctionless (JL) NWFET has been proposed to improve sensitivity for detecting various diseases. A comparative analysis of the dielectric modulated triple-hybrid metal gate-all-around JL-NWFET biosensor has been carried out with unique and double-hybrid metal gate (DHM) transistors immobilizing different biomolecules (neutral) such as streptavidin, ChO X, APTES, uricase, and biotin in the nanogap cavity region. The simulation results were analyzed using the Atlas-3D device simulation tool. The work shows that higher work-function and higher dielectric materials near the drain suppress/overcome short-channel effects and quantum mechanical tunneling caused by hot-carrier and electron scattering due to a high electric field and saturation velocity. The impact of neutral biomolecules on device output characteristics such as switching (ION/ IOFF) ratio, shifting threshold voltage (Δ Vth), intrinsic voltage gain (gm/ gd) , drain off-current sensitivity (SIOFF), subthreshold slope, transconductance (gm) , output conductance (gd) , surface potential and output resistance (1 / gd) has been studied. Sensitivity of the proposed device for detecting a specific neutral biomolecule was examined using a drain off-current ratio, and the results were compared with available works. The result shows a higher sensitivity in a triple-hybrid metal gate transistor than a unique and double-hybrid metal gate transistor in addition to available works, as we have discussed under the results and discussion section. For example, drain off-current sensitivity (SIOFF) in a triple-hybrid metal gate when a biotin biomolecule is immobilized uniformly in the nanogap cavity was 217.6% and 46.43% higher than a unique and double-hybrid metal gate transistor, respectively. We found that the proposed device can detect a specific biomolecule to diagnose different biomarkers for diseases such as breast and lung cancer.