Carbon Nanotube Field-Effect Transistors With Integrated Ohmic Contacts and High-k Gate Dielectrics

TL;DR

This paper demonstrates high-performance semiconducting carbon nanotube FETs with integrated ohmic contacts and high-k dielectrics, achieving high ON currents, low subthreshold swings, and improved OFF states for scaled devices.

Contribution

It introduces a novel combination of ohmic contacts, high-k gate dielectrics, and electrostatically doped source/drain segments to enhance CNTFET performance and scalability.

Findings

High ON currents achieved

Subthreshold swing of ~70-80 mV/decade

Low OFF currents and suppressed ambipolar conduction

Abstract

High performance enhancement mode semiconducting carbon nanotube field-effect transistors (CNTFETs) are obtained by combining ohmic metal-tube contacts, high dielectric constant HfO2 films as gate insulators, and electrostatically doped nanotube segments as source/drain electrodes. The combination of these elements affords high ON currents, subthreshold swings of ~ 70-80 mV/decade, and allows for low OFF currents and suppressed ambipolar conduction. The doped source and drain approach resembles that of MOSFETs and can impart excellent OFF states to nanotube FETs under aggressive vertical scaling. This presents an important advantage over devices with metal source/drain, or devices commonly referred to as Schottky barrier FETs.