Performance Evaluation of Dielectrically Modulated Extended Gate Single Cavity InGaAs/Si HTFET Based Label-Free Biosensor Considering Non-Ideal Issues

• Published in: IEEE sensors journal Vol. 21; no. 4; pp. 4739 - 4746
• Main Authors: Mukhopadhyay, Swarnav, Sen, Dipanjan, Goswami, Bijoy, Sarkar, Subir Kumar
• Format: Journal Article
• Language: English
• Published: New York IEEE 15-02-2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomolecules; biosensor; Biosensors; extended gate; Heterostructure TFET; Heterostructures; Indium gallium arsenides; label-free biosensing; Logic gates; Molecular biophysics; nanocavity; Performance evaluation; Permittivity; Sensitivity; Sensitivity analysis; Steric hindrance; TFETs; Tunneling
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2020.3033576

The dielectrically modulated heterostructure TFET based nanocavity embedded label-free biosensors are emerging as low power, highly sensitive bio-analyte detectors. High sensitivity and fast detection of biomolecules are still a challenge for researchers. In this article, single cavity dual-material extended gate heterostructure (III-V) TFET (SC-DM-EG HTFET) based dielectrically modulated label-free biosensor is proposed; which promises higher sensitivity and better device performances such as, ON current, <inline-formula> <tex-math notation="LaTeX">\text{I}_{ON}/\text{I}_{OFF} </tex-math></inline-formula>ratio, subthreshold swing (SS); compared with single cavity dual-material heterostructure TFET (SC-DM HTFET), dual cavity dual-material heterostructure TFET (DC-DM HTFET), as well as, previously proposed FET based biosensors. 2D numerical simulation of the biosensors was performed with SILVACO ATLAS 2D simulation software. III-V heterostructure (InGaAs/Si) and extended gate geometry provide increased tunneling probability, improved gate control, high <inline-formula> <tex-math notation="LaTeX">\text{I}_{ON}/\text{I}_{OFF} </tex-math></inline-formula>ratio, and ultra-high sensitivity, compared to IV-IV heterostructure biosensors. The sensitivities of the biosensors are analyzed for both neutral and charged biomolecules, with dielectric constants <inline-formula> <tex-math notation="LaTeX">\text{K}=5 </tex-math></inline-formula>,7,10,12. Effect of non-ideal issues on sensitivity, such as temperature fluctuation, steric hindrance are also studied for the biosensors mentioned above. Benchmarking is done to provide a quantitative comparison of the proposed biosensor with published literature. A maximum sensitivity of <inline-formula> <tex-math notation="LaTeX">1.3\times 10^{8} </tex-math></inline-formula>, along with the <inline-formula> <tex-math notation="LaTeX">\text{I}_{ON}/\text{I}_{OFF} </tex-math></inline-formula>ratio of <inline-formula> <tex-math notation="LaTeX">2\times 10^{12} </tex-math></inline-formula>and SS of 25.4 mV/V is noticed in SC-DM-EG HTFET for the dielectric constant of <inline-formula> <tex-math notation="LaTeX">\text{K}=12 </tex-math></inline-formula> in a completely filled cavity of neutral biomolecules.