Vertical Channel Dielectric Modulated Trench Dopingless Double Gate Junctionless FET Based Biosensor

This study introduces the Vertical Channel Dielectric-Modulated Trench Dopingless Double Gate Junctionless Field-Effect Transistor (VDM-TDLDGJLFET) biosensor, a novel design for biomolecule detection with enhanced sensitivity and simplified fabrication. The proposed device employs a dopingless architecture, utilizing charge plasma to create source/drain regions and incorporating vertically positioned gates in trenches to improve device control and sensitivity. The cavities for immobilizing biomolecules are precisely etched into the gate oxide area. Through 2D numerical simulations using the ATLAS TCAD simulator, the biosensor’s performance is analyzed, focusing on key parameters such as channel potential, drain current, threshold voltage, current/voltage sensitivity, and cavity fill-in factor (FF) sensitivity. The results reveal that the VDM-TDLDGJLFET biosensor exhibits superior gate control, enhanced sensitivity to dielectric constants and biomolecule charges, and improved subthreshold characteristics. A significant threshold voltage shift of 491 mV is observed as the dielectric constant of neutral biomolecules varies from 1 to 12, enabling effective biomolecule discrimination.