Direct Graphene Growth on Insulator

TL;DR

This paper demonstrates the direct growth of high-quality graphene on insulator surfaces like mica using molecular beam deposition, enabling better integration with silicon technology and functional device fabrication.

Contribution

It introduces a novel method for growing graphene directly on insulators, bypassing transfer issues and high-temperature constraints of traditional methods.

Findings

Successful planar graphene growth on mica surface.

Raman spectroscopy confirms film quality and growth parameter effects.

Evidence of electric field effect in a graphene transistor with directly grown channel.

Abstract

Fabrication of graphene devices is often hindered by incompatibility between the silicon technology and the methods of graphene growth. Exfoliation from graphite yields excellent films but is good mainly for research. Graphene grown on metal has a technological potential but requires mechanical transfer. Growth by SiC decomposition requires a temperature budget exceeding the technological limits. These issues could be circumvented by growing graphene directly on insulator, implying Van der Waals growth. During growth, the insulator acts as a support defining the growth plane. In the device, it insulates graphene from the Si substrate. We demonstrate planar growth of graphene on mica surface. This was achieved by molecular beam deposition above 600{\deg}C. High resolution Raman scans illustrate the effect of growth parameters and substrate topography on the film perfection. Ab initio calculations suggest a growth model. Data analysis highlights the competition between nucleation at surface steps and flat surface. As a proof of concept, we show the evidence of electric field effect in a transistor with a directly grown channel.