Noise diagnostics of graphene interconnects for atomic-scale electronics

László Pósa,Dávid Krisztián,Miklós Csontos,Zoltán Balogh,Roman Furrer,Péter Balázs,Botond Sánta,András Halbritter

doi:10.1038/s41699-021-00237-w

Abstract

Graphene nanogaps are considered as essential building blocks of two-dimensional electronic circuits, as they offer the possibility to interconnect a broad range of atomic-scale objects. Here we provide an insight into the microscopic processes taking place during the formation of graphene nanogaps through the detailed analysis of their low-frequency noise properties. Following the evolution of the noise level, we identify the fundamentally different regimes throughout the nanogap formation. By modeling the resistance and bias dependence of the noise, we resolve the major noise-generating processes: atomic-scale junction-width fluctuations in the nanojunction regime and sub-atomic gap-size fluctuations in the nanogap regime. As a milestone toward graphene-based atomic electronics, our results facilitate the automation of an optimized electrical breakdown protocol for high-yield graphene nanogap fabrication.

Highlights

Discovered 2D materials have demonstrated their high potential[1] as the versatile components of flexible[2] or siliconintegrated two-dimensional electronic circuits.[3]
Emerging applications include analog switches,[4,5,6] operational amplifiers,[7] flexible sensors,[8,9] or neuromorphic computing units.[10]. Most of these device concepts exploit the complex electronic properties of transition metal dichalcogenide structures,[11] whereas graphene is utilized as an ideal two-dimensional conducting and contacting platform
Graphene nanogaps are widely considered as ideal circuit components to clamp a broad range of further nanoscale objects, such as single molecules or molecular assemblies,[12,13,14,15] DNA sequences,[16,17] or atomic-scale resistive switching filaments.[18,19,20]

Summary

Introduction

Discovered 2D materials have demonstrated their high potential[1] as the versatile components of flexible[2] or siliconintegrated two-dimensional electronic circuits.[3]. Low resistance regime (RC < 3 ⋅ 103 Ω, red background) the relative current fluctuation remains at its low initial value of 10−3 (Fig. 3a), whereas the Lorentzian type noise has latter number is beyond the range of the transmission electron microscopy measurements, i.e., it is considered as a rough estimate reflecting subnanometer-sized, atomic-scale junctions.

Results

Conclusion