Formation of Graphene atop a Si adlayer on the C-face of SiC

Abstract

The structure of the SiC(000-1) surface, the C-face of the {0001} SiC surfaces, is studied as a function of temperature and of pressure in a gaseous environment of disilane (Si2H6). Various surface reconstructions are observed, both with and without the presence of an overlying graphene layer (which spontaneously forms at sufficiently high temperatures). Based on cross-sectional scanning transmission electron microscopy measurements, the interface structure that forms in the presence of the graphene is found to contain 1.4 - 1.7 monolayers (ML) of Si, a somewhat counter-intuitive result since, when the graphene forms, the system is actually under C-rich conditions. Using ab initio thermodynamics, it is demonstrated that there exists a class of Si-rich surfaces containing about 1.3 ML of Si that are stable on the surface (even under C-rich conditions) at temperatures above about 400 K. The structures that thus form consist of Si adatoms atop a Si adlayer on the C-face of SiC, with or without the presence of overlying graphene.

arXiv comment19 pages with 8 figures, along with 6 pages of Supplemental Material; v2 adds refs. 56,59-62 all being prior work, along with several paragraphs in the Discussion or Summary sections of the manuscript discussing this prior work; v3 corrects several typographical errors

References in corpus (22)

• Quasi-free Standing Epitaxial Graphene on SiC by Hydrogen Intercalation
• Electronic structure of epitaxial graphene layers on SiC: effect of the substrate
• Large area and structured epitaxial graphene produced by confinement controlled sublimation of silicon carbide
• Few layers graphene on 6H-SiC(000-1): an STM study
• The structural properties of the multi-layer graphene/4H-SiC(000-1) system as determined by Surface X-ray Diffraction
• Half integer quantum Hall effect in high mobility single layer epitaxial graphene
• Decoupling Graphene from SiC(0001) via Oxidation
• Comparison of Graphene Formation on C-face and Si-face SiC {0001} Surfaces
• Approaching ideal graphene: The structure of hydrogen-intercalated graphene on 6H-SiC(0001)
• Graphene formed on SiC under various environments: Comparison of Si-face and C-face
• Thermodynamic equilibrium conditions of graphene films on SiC
• Atomic and electronic structure of monolayer graphene on 6H-SiC(000-1)(3 x 3) : a scanning tunneling microscopy study
• Growth of thin graphene layers on stacked SiC surface in ultra high vacuum
• Silicon intercalation into the graphene-SiC interface
• Formation of Epitaxial Graphene on SiC(0001) using Vacuum or Argon Environments
• Interface Structure of Graphene on SiC(000-1)
• Growth of monolayer graphene on 8deg off-axis 4H-SiC (000-1) substrates with application to quantum transport devices
• Growth of Large Domain Epitaxial Graphene on the C-Face of SiC
• Why graphene growth is very different on the C face than on the Si face of SiC: Insights from surface equilibria and the (3$\times$3)-3C-SiC($\bar{\text{1}}\bar{\text{1}}\bar{\text{1}}$) reconstruction
• The stability of strained H:Si(105) and H:Ge(105) surfaces
• Formation of a Buffer Layer for Graphene on C-face SiC{0001}
• Formation of Graphene on SiC(000-1) Surfaces in Disilane and Neon Environments