Schottky-to-Ohmic Crossover in Carbon Nanotube Transistor Contacts

Abstract

For carbon nanotube transistors, as for graphene, the electrical contacts are a key factor limiting device performance. We calculate the device characteristics as a function of nanotube diameter and metal workfunction. Although the on-state current varies continuously, the transfer characteristics reveal a relatively abrupt crossover from Schottky to ohmic contacts. We find that typical high-performance devices fall surprisingly close to the crossover. Surprisingly, tunneling plays an important role even in this regime, so that current fails to saturate with gate voltage as was expected due to "source exhaustion".

6 pages, 4 figures

References in corpus (3)

• Doping graphene with metal contacts
• Enhanced Performance of Short-Channel Carbon Nanotube Field-Effect Transistors Due to Gate-Modulated Electrical Contacts
• Electrostatic effects on contacts to carbon nanotube transistors

Cited by in corpus (3)

• Short-Channel Field Effect Transistors with 9-Atom and 13-Atom wide Graphene Nanoribbons
• A Compact Virtual-Source Model for Carbon Nanotube Field-Effect Transistors in the Sub-10-nm Regime - Part II Extrinsic Elements, Performance Assessment, and Design Optimization
• Bandstructure and Contact Resistance of Carbon Nanotubes Deformed by the Metal Contact