Title :
Computational Study of the Ultimate Scaling Limits of CNT Tunneling Devices
Author :
Poli, Stefano ; Reggiani, Susanna ; Gnudi, Antonio ; Gnani, Elena ; Baccarani, Giorgio
Author_Institution :
Univ. of Bologna, Bologna
Abstract :
The ultimate scaling limits of p-i-n carbon-nanotube field-effect transistors (CNT-FETs) are investigated through numerical simulations based on a quantum-mechanical transport within the nonequilibrium Green´s function formalism, based on an energy-dependent effective mass, including inelastic phonon scattering. Starting from the projected specifications of the International Technology Roadmap for Semiconductors for the low-operating-power double-gate MOSFETs, the effect of variations of oxide thickness, power supply, and gate length has been systematically studied. The main conclusion is that there is no speed advantage in scaling the gate length of the p-i-n CNT-FETs below 16 nm due to the rapid increase of the tunneling current in the subthreshold region. A near optimum is found by keeping the gate length fixed at 16 nm and by scaling the oxide thickness and the power supply.
Keywords :
Green´s function methods; carbon nanotubes; nanotube devices; power MOSFET; quantum theory; tunnelling; CNT tunneling devices; International Technology Roadmap for Semiconductors; computational study; double-gate MOSFET; inelastic phonon scattering; low-operating-power MOSFET; nonequilibrium Green function; p-i-n carbon-nanotube field-effect transistors; quantum-mechanical transport; ultimate scaling limits; CNTFETs; Effective mass; Green´s function methods; MOSFETs; Numerical simulation; PIN photodiodes; Particle scattering; Phonons; Power supplies; Tunneling; Band-to-band-tunneling (BTBT) devices; carbon nanotubes (CNTs); nonequilibrium Green´s function (NEGF); transistor scaling;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2007.910563