Design and Performance Optimization of Novel Core-Shell Dopingless GAA-Nanotube TFET With Si0.5Ge0.5-Based Source

In this article, two nanotube structures have been proposed: namely, core–shell dopingless nanotube tunnel field effect transistor (CS-DL-NT-TFET) and Si0.5Ge0.5 source CS-DL-NT-TFET. The application of charge-plasma (CP) technique in their designing offers a fabrication advantage, which is the elimination of doping. Performance analysis of the two nanotube structures has been carried out on the basis of RF and analog parameters such as their transconductance ( ${g}_{m}$ ), transfer characteristics ( ${I}_{D}$ – ${V}_{{\text {GS}}}$ ), output conductance ( ${g}_{{\text {ds}}}$ ), output characteristics ( ${I}_{D}$ – ${V}_{{\text {DS}}}$ ), cut-off frequency ( ${f}_{T}$ ), and gate capacitance ( ${C}_{{\text {gg}}}$ ). Furthermore, the two devices have also been investigated for linearity and reliability based on parameters such as higher-order transconductances ( ${g}_{{\textit {m3}}}$ and ${g}_{{\textit {m2}}}$ ), distortions [second-order harmonic distortion (HD2)], interception points [third-order input interception point (IIP3), second-order voltage interception point (VIP2), and third-order voltage interception point (VIP3)], and intermodulation distortion [third-order intermodulation distortion (IMD3)]. Based on the analysis of different parameters, the Si0.5Ge0.5 source CS-DL-NT-TFET was observed to have achieved an improved performance as compared to its Si-source counterpart due to a lower energy bandgap, higher mobility, and lower tunneling mass. The proposed device is optimized to maintain the uniformity of the induced CP within the source/drain regions. The optimized architecture enhances the device performance by attaining an average subthreshold slope of 31.38 mV/dec with a higher ON-current.