Low-Temperature Growth of Graphene on a Semiconductor

Håkon I Røst,Zheshen Li,Benjamen P Reed,Antonija Grubišić-Čabo,Anton Tadich,Bruce C C Cowie,Simon P Cooil,Rajesh Kumar Chellappan,Thomas Schmidt,Justin W Wells,Mauricio J Prieto,Lucas De Souza Caldas,Thipusa Wongpinij,Liviu C Tǎnase,Frode S Strand,Chanan Euaruksakul

doi:10.1021/acs.jpcc.0c10870

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.

Highlights

Since its experimental discovery in 2004,1 graphene a twodimensional carbon crystal in a honeycomb structure has been deemed a promising candidate for device applications because of its exceptional electronic, thermal, optical, and mechanical properties.[2−6] the challenges associated with the production of large-scale high-quality graphene layers directly on semiconductor substrates have limited the integration of graphene with conventional device prototypes
This metal-mediated approach leaves graphene resting on underlying layers of metal silicide, which can be eliminated by subsequent thermal treatments to higher temperatures, driving diffusion of the metal ions into the bulk crystal.[21]
The metal-mediated growth of epitaxial few-layer graphene on the surface of 6H-SiC(0001) treated with Fe or Ru has been investigated, at a temperature far lower than that required for graphene growth directly from the SiC crystal

Summary

Introduction

Since its experimental discovery in 2004,1 graphene a twodimensional carbon crystal in a honeycomb structure has been deemed a promising candidate for device applications because of its exceptional electronic, thermal, optical, and mechanical properties.[2−6] the challenges associated with the production of large-scale high-quality graphene layers directly on semiconductor substrates have limited the integration of graphene with conventional device prototypes.Until now, the most common techniques for preparing monolayer graphene include micromechanical exfoliation from bulk graphite, epitaxial growth on various transition metals[7−10] through chemical vapor deposition (CVD) of hydrocarbons, and thermal decomposition of bulk crystals such as silicon carbide.[11,12] Among these methods, epitaxial growth by CVD and thermal decomposition of SiC are normally favored as large-area single-crystalline graphene domains can be achieved routinely.[13−15] CVD grown graphene requires an additional transfer step onto a suitable substrate, limiting the scalability of the technique when it comes to producing graphene on a semiconductor or dielectric of uniform size and quality. A similar method has previously been successfully demonstrated at temperatures of 500−600 °C by using Fe on both SiC and diamond.[19,20] Here, we show that ordered graphene layers can be produced from SiC by using either Fe or Ru, with an onset of growth starting at around 450−500 °C. This metal-mediated approach leaves graphene resting on underlying layers of metal silicide, which can be eliminated by subsequent thermal treatments to higher temperatures, driving diffusion of the metal ions into the bulk crystal.[21] The result is quasi-freestanding graphene resting

Methods

Results

Conclusion