Advancements in Complementary Carbon Nanotube Field-Effect Transistors

TL;DR

This paper reports on high-performance p- and n-type SWNT FETs with tunable contacts, demonstrating their potential for complementary nanoelectronics and addressing key issues like hysteresis and threshold control.

Contribution

It introduces a method to achieve high-performance SWNT FETs with tunable contacts using different metals, enabling complementary logic applications.

Findings

High ON-state currents up to 20 μA per tube.

Tunable barrier heights via contact metal choice.

Successful demonstration of an inverter using these FETs.

Abstract

High performance p- and n-type single-walled carbon nanotube (SWNT) field-effect transistors (FETs) are obtained by using high and low work function metals, Pd and Al as source/drain (S/D) electrodes respectively. Ohmic contacts made to chemically intrinsic SWNTs, with no or small Schottky barriers (SB), afford high ON-state currents up to 20 uA per tube. The lack of significant Fermi-level pinning at the nanotube-metal interfaces allows for fine-tuning of the barrier heights for p-and n-channel conductions by changing the contact metals. The air-stable p- and n-FETs thus obtained can be used for complementary nanoelectronics, as demonstrated with the fabrication of an inverter. Other important issues regarding nanotube FETs including hysteresis, OFF-state leak currents, choice of nanotube diameter, and threshold voltage control are discussed.