Electronic and chemical passivation of hexagonal 6H–SiC surfaces by hydrogen termination

Sieber, N.; Mantel, B.F.; Seyller, Thomas; Ristein, J.; Ley, L.; Heller, Thomas; Batchelor, David; Schmeißer, Dieter

doi:10.1063/1.1351845

Cited by 88 publications

(67 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second gap is caused by the coupling of the plasmon to the Si-H stretching vibration at the graphene/SiC interface. Consequently, ω + converges to 2090 cm −1 for high momentum transfers, while ω ++ converges to the Si-H stretching frequency of 2130 cm −1 for q → 0 which was previously observed by infrared absorption spectroscopy [19,33,34] where the momentum transfer is very small. Now we turn to the water intercalated sample [ fig.…”

supporting

confidence: 72%

Robust Phonon-Plasmon Coupling in Quasifreestanding Graphene on Silicon Carbide

et al. 2016

Self Cite

View full text Add to dashboard Cite

supporting

confidence: 72%

Robust Phonon-Plasmon Coupling in Quasifreestanding Graphene on Silicon Carbide

et al. 2016

Self Cite

View full text Add to dashboard Cite

“…42,43 In previous studies 44 -48 we have investigated the chemical, electronic, and structural properties of 6H-SiC͕0001͖ surfaces that were hydrogenated by the method of Tsuchida et al The hydrogenated surfaces with (1ϫ1) periodicity were observed to be free of unwanted contaminations such as oxygen and hydrocarbons. 44 We were also able to show that the density of charged defects on SiC͑0001͒ can be pushed down to values of 7ϫ10 10 cm…”

Section: Introductionmentioning

confidence: 88%

Synchrotron x-ray photoelectron spectroscopy study of hydrogen-terminated6H−SiC{0001}surfaces

et al. 2003

Self Cite

View full text Add to dashboard Cite

We report on highly resolved core-level and valence-band photoemission spectroscopies of hydrogenated, unreconstructed 6H-SiC(0001) and (0001 ) using synchrotron radiation. In the C 1s core level spectra of 6H-SiC(0001 ) a chemically shifted surface component due to C-H bonds is observed at a binding energy (0.47Ϯ0.02) eV higher than that of the bulk line. The Si 2p core-level spectra of SiC (0001) suggest the presence of a surface component as well but a clear identification is hindered by a large Gaussian width, which is present in all spectra and which is consistent with values found in the literature. The effect of thermal hydrogen desorption was studied. On 6H-SiC(0001) the desorption of hydrogen at 700-750°C is accompanied by a simultaneous transformation to the Si-rich (ͱ3ϫͱ3)R30°reconstruction. On 6H-SiC(0001 ) first signs of hydrogen desorption, i.e., the formation of a dangling bond state in the fundamental band gap of SiC, are seen at temperatures around 670°C while the (1ϫ1) periodicity is conserved. At 950°C a (3ϫ3) reconstruction is formed. The formation of these reconstructions on thermally hydrogenated 6H-SiC (0001) and (0001 ) is discussed in the light of earlier studies of 6H-SiC͕0001͖ surfaces. It will be shown that by using the hydrogenated surfaces as a starting point it is possible to gain insight into how the (ͱ3ϫͱ3)R30°and (3ϫ3) reconstructions are formed on 6H-SiC(0001) and 6H-SiC(0001 ), respectively. This is due to the fact that only hydrogen-terminated 6H-SiC͕0001͖ surfaces possess a surface carbon to silicon ratio of 1:1.

show abstract

“…Whereas the calculated Schottky barriers are referenced to the E VBM , the SiC substrates used in the experiments are n-type with the bulk Fermi level a few tenth of eV below the conduction band edge 22 . The use of E VBM as the reference is consistent with the freestanding nature of the transferred graphene and the Fermi level pinning within the SiC gap near the valence band edge 37 .…”

Section: Discussionmentioning

confidence: 99%

“…2b). This processing additionally leads to a chemically inert surface likely terminated with hydrogen or silicates 22,23 , which protects the SiC surface from oxidation during the transfer of graphene.…”

Section: Band Alignment Of Graphene and H-terminated Silicon Carbidementioning

confidence: 99%

Spatial fluctuations in barrier height at the graphene–silicon carbide Schottky junction

et al. 2013

View full text Add to dashboard Cite

When graphene is interfaced with a semiconductor, a Schottky contact forms with rectifying properties. Graphene, however, is also susceptible to the formation of ripples upon making contact with another material. Here we report intrinsic ripple-and electric field-induced effects at the graphene semiconductor Schottky junction, by comparing chemical vapourdeposited graphene transferred on semiconductor surfaces of opposite polarization-the hydrogen-terminated silicon and carbon faces of hexagonal silicon carbide. Using scanning tunnelling microscopy/spectroscopy and first-principles calculations, we show the formation of a narrow Schottky dipole barrier approximately 10 Å wide, which facilitates the observed effective electric field control of the Schottky barrier height. We further find atomic-scale spatial fluctuations in the Schottky barrier that directly follow the undulation of ripples on both graphene-silicon carbide junctions. These findings reveal fundamental properties of the graphene/semiconductor Schottky junction-a key component of vertical graphene devices that offer functionalities unattainable in planar device architecture.

show abstract

Electronic and chemical passivation of hexagonal 6H–SiC surfaces by hydrogen termination

Cited by 88 publications

References 12 publications

Robust Phonon-Plasmon Coupling in Quasifreestanding Graphene on Silicon Carbide

Robust Phonon-Plasmon Coupling in Quasifreestanding Graphene on Silicon Carbide

Synchrotron x-ray photoelectron spectroscopy study of hydrogen-terminated6H−SiC{0001}surfaces

Spatial fluctuations in barrier height at the graphene–silicon carbide Schottky junction

Contact Info

Product

Resources

About