Graphene as a p-type metal for ultimate miniaturization

TL;DR

This paper demonstrates scalable, high-conductivity bilayer graphene sheets with high hole concentrations and low resistance, stable over time and air exposure, suitable for miniaturized electronic devices.

Contribution

It introduces a reliable, high-throughput growth process for large-area bilayer graphene with exceptional electrical properties and enhanced adhesion, advancing graphene integration in semiconductor technology.

Findings

Achieved high hole concentration (~10^{15} cm^{-2}) in bilayer graphene.

Obtained low sheet resistance of 20-25 Ω/□ over large areas.

Demonstrated stability of properties over thermal anneals and air exposure.

Abstract

We report macroscopic sheets of highly conductive bilayer graphene with exceptionally high hole concentrations of ~ $10^{15}$ $cm^{-2}$ and unprecedented sheet resistances of 20-25 {\Omega} per square over macroscopic scales, and obtained in-situ over a thin cushion of molecular oxygen on a silicon substrate. The electric and electronic properties of this specific configuration remain stable upon thermal anneals and months of exposure to air. We further report a complementary ab-initio study, predicting an enhancement of graphene adhesion energy of up to a factor 20, also supported by experimental fracture tests. Our results show that the remarkable properties of graphene can be realized in a reliable fashion using a high-throughput process. In addition to providing exceptional material properties, the growth process we employed is scalable to large areas so that the outstanding conduction properties of graphene can be harnessed in devices fabricated via conventional semiconductor manufacturing processes. We anticipate that the approach will provide the necessary scalability and reliability for future developments in the graphene nanoscience and technology fields, especially in areas where further miniaturization is hampered by size effects and electrical reliability of classical conductors.