Negative capacitance source pocket double gate tunnel FET as a label-free dielectrically modulated biosensor

Abstract This article examines the potential use of Negative Capacitance Source Pocket Double Gate Tunnel Field Effect Transistor (NC-SP-DGTFET) as a biosensor capable of detecting the biomolecules present in the nanocavity. The proposed biosensor incorporated a gate dielectric engineering along with the channel engineering method and asymmetrical doping at source and drain regions. In addition, a nanocavity is formed by selectively removing a section of the gate dielectric at the source and drain ends to accompany the biomolecules in the device. The biosensing performance measures Threshold Voltage Sensitivity ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>S</mml:mi> </mml:mrow> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>V</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">th</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:msub> </mml:math> ), I ON /I OFF Current Ratio Sensitivity ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>S</mml:mi> </mml:mrow> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>I</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">ON</mml:mi> </mml:mrow> </mml:msub> <mml:mo>/</mml:mo> <mml:msub> <mml:mrow> <mml:mi>I</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">OFF</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:msub> </mml:math> ), and Drain Current Sensitivity ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>S</mml:mi> </mml:mrow> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>I</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">DS</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:msub> </mml:math> ), with 60.3, 372.3, and 395.4 respectively are observed with neutral charge of biomolecules. The investigation involves biomolecules with positive and negative charges, which are tested under different dielectric constants in the nanocavity. In addition, an extensive investigation of a partially filled nanocavity caused by steric hindrance has been presented to capture the current situation. The study examined several scenarios with partially filled nanocavities to analyze the sensitivity characteristics, including convex, concave, increasing, and decreasing step profiles, as well as the positioning of the probe in an asymmetric manner. The study compares several sensitivity characteristics of the NC-SP-DGTFET with existing biosensors to determine the effectiveness of the proposed biosensor. The NC-SP-DGTFET biosensor outperforms traditional TFET-based biosensors by using a ferroelectric material as the oxide material. This choice of material enhances the subthreshold slope, increases gate control over the channel, and demonstrates its suitability for low-power biosensor design.