Scaling limits of graphene nanoelectrodes

TL;DR

This paper investigates the limits of graphene nanoelectrodes, revealing a scaling limit of approximately 10 nm due to intrinsic resistance switching caused by carbon filament formation and breakdown.

Contribution

It demonstrates the voltage-driven resistance switching in sub-5 nm graphene nanogaps and establishes a fundamental scaling limit for device miniaturization.

Findings

Resistance switching occurs in sub-5 nm gaps

Switching is due to carbon filament formation and breakdown

Scaling limit of approximately 10 nm for device operation

Abstract

Graphene is an ideal material for fabricating atomically thin nanometre spaced electrodes. Recently, carbon-based nanoelectrodes have been employed to create single-molecule transistors and phase change memory devices. In spite of the significant recent interest in their use in a range of nanoscale devices from phase change memories to molecular electronics, the operating and scaling limits of these electrodes are completely unknown. In this paper, we report on our observations of consistent voltage driven resistance switching in sub-5 nm graphene nanogaps. We find that we are able to reversibly cycle between a low and a high resistance state using feedback-controlled voltage ramps.We attribute this unexplained switching in the gap to the formation and breakdown of carbon filaments.By increasing the gap, we find that such intrinsic resistance switching of graphene nanogaps imposes a scaling limit of 10 nm (approx.) on the gap-size for devices with operating voltages of 1 to 2 volts.