High Performance N-Type Carbon Nanotube Field Effect Transistors with Chemically Doped Contacts

TL;DR

This paper demonstrates high-performance n-type carbon nanotube FETs with chemically doped contacts, achieving high on-currents, low subthreshold swing, and high on/off ratios, showing promise for future electronics.

Contribution

It introduces chemically doped contacts in short-channel SWNT FETs, significantly improving their electrical performance over previous designs.

Findings

High on-currents comparable to silicon n-MOSFETs

Subthreshold swing of 70 mV/decade

On/off ratio up to 10^6 at 0.5V

Abstract

Short channel (~80 nm) n-type single-walled carbon nanotube (SWNT) field-effect transistors (FETs) with potassium (K) doped source and drain regions and high-k gate dielectrics (ALD HfO2) are obtained. For nanotubes with diameter ~ 1.6 nm and bandgap ~ 0.55 eV, we obtain n-MOSFET-like devices exhibiting high on-currents due to chemically suppressed Schottky barriers at the contacts, subthreshold swing of 70mV/decade, negligible ambipolar conduction and high on/off ratios up to 10^6 at a bias voltage of 0.5V. The results compare favorably with the state-of-the-art silicon n-MOSFETs and demonstrate the potential of SWNTs for future complementary electronics. The effects of doping level on the electrical characteristics of the nanotube devices are discussed.