Performance analysis and design optimization of near ballistic carbon nanotube field-effect transistors

A near ballistic carbon nanotube field-effect transistor (CNTFET) that integrates an ultra-short channel, low-barrier metal contacts, and a thin high-K gate insulator is modeled and analyzed using self-consistent quantum simulations. Numerical simulations, which solve a quantum transport equation self-consistently with a 3D Poisson equation using the non-equilibrium Green´s function (NEGF) formalism, are used to understand the transistor physics and to suggest design optimization. Important device issues of: (1) how close the transistor operates to its ballistic limit; (2) what are the roles of phonon scattering and higher subband conduction; (3) how to further optimize the CNTFET; and (4) how the CNTFET compares to a state-of-the-art Si MOSFET, are explored and discussed.