Performance Assessment of Graded Channel Gate-Stack based Double Gate MOSFET for Bio-sensing Applications

In this paper, the performance of the Asymmetric Gate Graded Channel Gate-Stack Double Gate (AG-GCGS-DG) MOSFET-based biosensor has been investigated for dielectric-modulated (DM) label-free sensing of neutral and charged biomolecules present in the cavity region. The efficiency of the AG-GCGS-DG MOSFET-based biosensor has been evaluated to compare with the Symmetric Gate (SG) GCGS-DG MOSFET-based biosensor in terms of different sensitivity metrics such as threshold voltage, On state current, subthreshold swing and drain current sensitivity. The asymmetric gate (AG) type biosensor shows 290%, 7%, 96% and 103% improvement in threshold voltage, On state current, subthreshold swing and drain current sensitivity as compared to the symmetric gate (SG) based biosensor. Linearity characteristics of asymmetric and symmetric gate-based biosensors have been studied in terms of higher order derivatives of transconductance, voltage intercept point, extrapolated input power point, and intermodulation distortion. The asymmetric gate biosensor shows better linearity performance compared to the symmetric gate-based biosensor.