Tunneling Carbon Nanotube Field Effect Transistor with Asymmetric Graded Double Halo Doping in Channel: Asym-GDH-T-CNTFET

A tunneling carbon nanotube field effect transistor with asymmetric graded double halo (asym-GDH-T-CNTFET) is investigated in order to enhance band to band tunneling and evaluate the device characteristics by non-equilibrium Green's function (NEGF) method. The asym-GDH-T-CNTFET structure includes in n-doped halo at the source side and p-doped halo at the drain side which covered through the channel. The source-side halo doping, reduces short-channel effect (SCE) and drain induced barrier lowering (DIBL) and the drain-side halo doping reduces drain energy barrier and increases band to band tunnelling in drain contact, subsequently. The asym-GDH-T-CNTFET has represented a higher tunneling current compared to T-CNTFET. Sub-threshold swing increases and ON/OFF current ratio decreases using of asymmetric graded double halo tunnelling carbon nanotube field effect transistor when compared to that of tunnelling carbon nanotube field effect transistor (T-CNTFET). In this paper, we investigate on-state current, tunneling-current and also characteristics of the asym-GDH-T-CNTFET compares to T-CNTFET.