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

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 (I-ON/I-OFF) ratio, shifting threshold voltage (Delta V-th), intrinsic voltage gain (g(m)/g(d)), drain off-current sensitivity (S-IOFF), subthreshold slope, transconductance (g(m)), output conductance (g(d)), surface potential and output resistance (1/g(d)) 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 (S-IOFF) 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.