Novel attributes and design considerations of source and drain regions in carbon nanotube transistors

Source and drain regions are inseparable sections of carbon nanotube field effect transistor (CNTFET) whose parameters are effective for CNTFET performance. For the first time in this paper, design considerations of source and drain regions are presented by developing a two-dimensional (2-D) full quantum simulation. The simulations have been done by the self-consistent solution of 2-D Poisson–Schrödinger equations, within the nonequilibrium Green’s function (NEGF) formalism. The effects of varying the source and drain parameters are investigated in terms of on–off current ratio, transconductance characteristics, drain conductance, and subthreshold swing. Simulation results demonstrate that we could improve the CNTFET performance with proper selection of the source and drain parameters.