Low Temperature Growth of Graphene on Semiconductor

TL;DR

This study demonstrates low-temperature growth of high-quality graphene on SiC substrates via chemical reactions with Fe and Ru, enabling scalable device fabrication.

Contribution

It introduces a novel low-temperature process for growing graphene on semiconductors using transition metal treatments, improving reproducibility and quality.

Findings

Graphene growth initiates at 450-500°C on treated SiC.

Chemical reaction liberates sp3 carbon, converting to sp2 graphene.

Graphene quality confirmed by spectroscopy techniques.

Abstract

The industrial realization of graphene has so far been limited by challenges related to the quality, reproducibility, and high process temperatures required to manufacture graphene on suitable substrates. We demonstrate that epitaxial graphene can be grown on transition metal treated 6H-SiC(0001) surfaces, with an onset of graphitization starting around $450-500^\circ\text{C}$. From the chemical reaction between SiC and thin films of Fe or Ru, $\text{sp}^{3}$ carbon is liberated from the SiC crystal and converted to $\text{sp}^{2}$ carbon at the surface. The quality of the graphene is demonstrated using angle-resolved photoemission spectroscopy and low-energy electron diffraction. Furthermore, the orientation and placement of the graphene layers relative to the SiC substrate is verified using angle-resolved absorption spectroscopy and energy-dependent photoelectron spectroscopy, respectively. With subsequent thermal treatments to higher temperatures, a steerable diffusion of the metal layers into the bulk SiC is achieved. The result is graphene supported on magnetic silicide or optionally, directly on semiconductor, at temperatures ideal for further large-scale processing into graphene based device structures.