Sensitivity Investigation of Underlap Gate Cavity-Based Reconfigurable Silicon Nanowire Schottky Barrier Transistor for Biosensor Application

Abstract

This study investigates the sensitivity of Underlap Gate Cavity-based Reconfigurable Silicon Nanowire Schottky Barrier Transistor (UCG-RSiNW SBT) with an underlap gate-drain region for biosensing application. The featured unique reconfigurable capability enables the device to operate as either p-type or n-type, dependent on the applied bias polarity. The proposed biosensor incorporates a cavity beneath the control gate on the source side, facilitating the placement of both neutral and charged biomolecules with varying dielectric constant (K) values. Upon injection of biomolecules into the cavity, the device changes electrostatic characteristics, including modulation in threshold voltage, potential, electric field, and sub-threshold swing, \(I_{ON}\), \(I_{ON}\)/\( I_{OFF}\) ratio. The threshold voltage (\(V_{TH}\)) Sensitivity of n-mode is enhanced by \(97.91\%\), while that of p-mode is raised by \(16\%\) compared to conventional RFET biosensors. The drain current sensitivity and the linearity of proposed biosensor is enhanced upto the values of 2792 and 0.997 respectively in n-mode configuration whereas in p-mode configuration, the drain current sensitivity and the linearity comes out to be 968 and 0.995 respectively. These high sensitivity and linearity values make this biosensor superior to the existing state-of-the-art biosensors. The findings from this study provide valuable insights into the development of highly sensitive biosensors for applications in diverse fields, including healthcare and biotechnology.