Enhanced Biosensing with Double Gate Junctionless FET based on III-V Compound Semiconductor and Symmetric Cavity for Label-Free Detection of Neutral and Charged Biomolecules

This paper introduces a novel dielectric engineered AlAs/GaAs-based double gate junctionless FET (AlAs/GaAs-DGJLFET) for label-free detection in biosensor applications. The AlAs/GaAs-DGJLFET utilizes dielectric engineering and modulation techniques to detect major food analytes such as Gluten, Zenine, Keratin, and Gelatin. The proposed device incorporates high-K spacers (HfO2 regions) and low-K spacers (SiO2 regions). Additionally, the biosensor features vertically placed gates in separate trenches, with cavities in the gate oxide region for biomolecule immobilization. The presence of neutral/charged biomolecules in the cavities leads to changes in the electrical parameters of the device. To demonstrate the effectiveness of the proposed biosensor, various electrical parameters such as conduction band energy distribution, electron concentration, electric field, channel potential, threshold voltage, subthreshold slope, ION/IOFF ratio, transconductance, cutoff-frequency, and more are evaluated. The results indicate enhancements in responsivity, sensitivity, selectivity, and linearity. Based on the simulation results, the incorporation of AlAs/GaAs heterostructure in the DGJLFET-based biosensor channel leads to a significant enhancement in the sensitivity of the ION/IOFF ratio by approximately 3.45 x 1011% for the neutral Gelatine biomolecule with K = 12. Additionally, the biosensor achieves approximately 480% and 40% improvements in threshold voltage and sub-threshold voltage sensitivity, respectively, for Gelatin. Therefore, the proposed biosensor exhibits superior electrical characteristics compared to recent literature on DGJLFET-based biosensors, while also offering the advantage of operating at low voltages. These findings highlight the potential of the proposed biosensor for advanced label-free detection in various biosensing applications.