Design and Performance Investigation of SiGe Heterojunction Based Vertical Dual Pocket Biosensor Design Based on Charge Plasma TFET

The downscaling of FET devices has begun to constrain the performance aspects of their applications, forcing researchers to adopt and investigate newer alternative designs to meet the required standards. Again, maintaining a consistent doping concentration across the device may lead to complications such as Random Dopant Fluctuations (RDF) and thermal budgeting, which can impede device outputs. This publication focuses on a vertical dual pocket biosensor design based on junctionless SiGe-Heterostructured TFET using charge-plasma technology to alleviate the RDF limitations while enhancing the tunneling process. In addition, the amount of biomolecules in the pockets impacts the device's sensitivity. To enhance the space available for trapping biomolecules, it is beneficial to either lengthen the pockets or add additional pockets. Due to the modification in dielectric constants (k) and charge densities, an increase in the trapping area adds to a quicker alteration of the sensor's electric characteristics. The additional area boosts the device's overall sensitivity to 7.78×10
⁸
when neutrally charged DNA (k=8.7) molecules are present and to 3.50×10
⁹
when positively charged. With the enhanced sensitivity provided by the auxiliary pocket design and the simplified production procedure due to the charge plasma method, this study may serve as a blueprint for future research into ultrasensitive biosensor alternatives.