The effects of elliptical gate cross section on carbon nanotube gate-all-around field effect transistor

In this paper, the gate-all-around carbon nanotube field effect transistor (FET) with elliptical shaped gate is studied with numerical simulation to explore the gate dielectric variation effects. The simulations are carried out with the three dimensional self-consistence Poisson-Schrodinger equations with the non-equilibrium Green´s function method. The on current, potential distribution, local density of states, and transmission coefficients of the devices of different geometry are examined. The performances of elliptical shaped gate device are compared to the round shaped gate ones and it is observed that the geometry has notable effects on the characteristics of the devices.