Studies of interfacial layers between 4H-SiC (0 0 0 1) and graphene

• Published in: Carbon (New York) 2010-04, Vol.48 (5), p.1670-1673
• Main Authors: Park, J.H., Mitchel, W.C., Smith, H.E., Grazulis, L., Eyink, K.G.
• Format: Article
• Language: English
• Subjects: Bonding; Carbon; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Graphitization; Materials science; Molecular beam epitaxy; Physics; Silicon; Silicon carbide; Specific materials; Spectra
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2009.12.006

The region between epitaxial graphene and the SiC substrate has been investigated. 4H-SiC (0001) samples were annealed in a high temperature molecular beam epitaxy system at temperatures between 1100 and 1700°C. The interfacial layers between the pristine SiC and the graphene layers were studied by X-ray photoelectron spectroscopy. Graphene was found to grow on the SiC surface at temperatures above 1200°C. Below this temperature, however, sp3 bonded carbon layers were formed with a constant atomic Si concentration. C1s and Si2p core level spectra of the graphene samples suggest that the interface layer we observe has a high carbon concentration and its thickness increases during the graphitization process. A significant concentration of Si atoms is trapped in the interface layer and their concentration also increases during graphitization.