Dielectric Modulated π-gate Junctionless FinFET-Based Biosensor: Improving Performance, Temperature Reliability and Sensitivity
摘要
This paper presents a dielectric modulated (DM) Si on 4 H-SiC π-gate junctionless FinFET (JLFinFET)-based biosensor for label-free biomolecule detection. The device features a 25 nm gate length with nanocavities on both sides of the fin. The incorporation of 4 H-SiC serves two key purposes: optimizing device performance through bandgap engineering and mitigating self-heating effects, a common issue in SOI devices that can potentially influence biomolecules and result in false detections. Compared to conventional JLFinFET designs, the proposed SoS-JLFinFET demonstrates superior characteristics, achieving 68% lower IOFF, a 200% increase in switching ratio (ION/IOFF), and a 69% improvement in transconductance (gm) while maintaining a similar ION. Additionally, the maximum lattice temperature is reduced by 76 K, significantly improving thermal reliability. Electrical characteristics, including transfer curves, ION/IOFF, gm, and gm/ID, have been analyzed to evaluate the device’s sensitivity. The biosensor demonstrates exceptional sensitivity in terms of IOFF, ION/IOFF, maximum ΔION, maximum Δgm, and gm/ID, with improvements of up to 50%, 14.5%, 101%, 52%, and 43% for K = 1.52 (lowest K value) and 99.999%, 88.9%, 3.6 × 107%, 305%, and 1750% for K = 12 (highest K value). The device maintains reliable operation across a broad temperature range (250–375 K). These results establish the SoS-JLFinFET as a highly sensitive and thermally robust biosensor, well-suited for integration with silicon-based data analysis circuits.