Initial Stages of the Graphite-SiC(0001) Interface Formation Studied by Photoelectron Spectroscopy

Abstract

Graphitization of the 6H-SiC(0001) surface as a function of annealing temperature has been studied by ARPES, high resolution XPS, and LEED. For the initial stage of graphitizationthe 6√3 reconstructed surface -we observe σ-bands characteristic of graphitic sp 2 -bonded carbon. The π-bands are modified by the interaction with the substrate. C1s core level spectra indicate that this layer consists of two inequivalent types of carbon atoms. The next layer of graphite (graphene) formed on top of the 6√3 surface at T A =1250°C-1300°C has an unperturbed electronic structure. The annealing at higher temperatures results in the formation of a multilayer graphite film. It is shown that the atomic arrangement of the interface between graphite and the SiC(0001) surface is practically identical to that of the 6√3 reconstructed layer.

Epitaxial Graphenes on Silicon Carbide

“…22,31,[45][46][47][48][49] The growth proceeds from step edges, with the decomposing layers first forming a (6√3x 6√3)R30° carbon rich surface reconstruction known as the "buffer layer" or "layer 0." 32,45,46,48,50 The exact atomic structure of layer 0 is not known experimentally, but the carbon density is very close to that of a graphene monolayer.…”

“…22,31,[45][46][47][48][49] The growth proceeds from step edges, with the decomposing layers first forming a (6√3x 6√3)R30° carbon rich surface reconstruction known as the "buffer layer" or "layer 0." 32,45,46,48,50 The exact atomic structure of layer 0 is not known experimentally, but the carbon density is very close to that of a graphene monolayer. 41,48,49 Both ARPES measurements 45,48,51 and theory 50,52,53 suggest that this layer consists of graphene-like sp 2 -bonded carbon, but the π orbitals interact with the SiC substrate strongly enough to create an energy band gap, determined from experiment to be ≥0.3 eV.…”

“…32,45,46,48,50 The exact atomic structure of layer 0 is not known experimentally, but the carbon density is very close to that of a graphene monolayer. 41,48,49 Both ARPES measurements 45,48,51 and theory 50,52,53 suggest that this layer consists of graphene-like sp 2 -bonded carbon, but the π orbitals interact with the SiC substrate strongly enough to create an energy band gap, determined from experiment to be ≥0.3 eV. 46 The energy gap increases to 1.5 eV with the adsorption of atomic hydrogen, which binds to the buffer layer but less readily to subsequent graphene layers.…”

Probing Electronic Properties of Graphene on the Atomic Scale by Scanning Tunneling Microscopy and Spectroscopy

“…This √ reconstruction on SiC(0001) was rst studied by van Bommel et al in 1975 [140], and has been interpreted with di erent models [141][142][143][144][145][146][147][148][149].…”

Growth, study, and device application prospects of graphene on SiC substrates

“…There have been several publications reporting that graphene films were obtained on the SiC surface. The communications [12,13]demonstrated that a graphene film can be obtained in a high vacuum (∼ 10 −10 Torr) on axis 6H-SiC wafer by the surface thermal decay method. In [14], planar monoatomic carbon films formed on a 4H silicon carbide wafer were also studied.…”