Design of Charge-Plasma-based Cylindrical-Gate-Nanowire TFET with low power and enhanced sensitivity for bio-sensing

Abstract

This paper proposes a Charge-Plasma-based Cylindrical-Gate-Nanowire Tunnel Field Effect Transistor (CPCG-NWTFET) and High-k Gate Stack Charge-Plasma-based Cylindrical-Gate-Nanowire Tunnel Field Effect Transistor (HKGS-CPCG-NWTFET) with the dielectric modulated split-gate label-free biosensor. Charged and uncharged (neutral) biomolecules with the different values of dielectric constants (K) are considered as sensing elements. As the biomolecules are introduced in the cavity, the value of the dielectric constant in the cavity is changed, which in turn changes the OFF-current, ON-current and threshold voltage (Vth) which are considered as the sensitivity parameters for sensing the biomolecules. The technique used in designing of cylindrical-gate-nanowire TFET-based biosensor is charged plasma. Various fill factors, e.g. 12%, 26%, 42%, 59%, 79% and 100% are used to observe its effect on the sensitivity. The proposed CPCG-NWTFET structure shows enhanced characteristics in many respects. The subthreshold slope (SS) is improved with fill factor and high dielectric constant. The sensitivity of the CPCG-NWTFET biosensor is high as compared to HKGS-CPCG-NWTFET. Maximum sensitivity enhancement calculated with the positive and negative charge of biomolecules with respect to SON and SOFF for CPCG-NWTFET is 13.8%, 14.2% and 23,337.2%, 538.1%, respectively. Similarly, maximum sensitivity enhancement with respect to SOFF for CPCG-NWTFET with fill factors (FF) is 13953.2%, whereas the sensitivity with respect to SON is higher for HKGS-CPCG-NWTFET. Thus, CPCG-NWTFET is a strong candidate for charge-plasma-based biosensor with low power and enhanced sensitivity.