High Electron Mobility in Epitaxial Graphene on 4H-SiC(0001) via post-growth annealing under hydrogen

Abstract

We investigate the magneto-transport properties of epitaxial graphene single-layer on 4H-SiC(0001), grown by atmospheric pressure graphitization in Ar, followed by H2 intercalation. We directly demonstrate the importance of saturating the Si dangling bonds at the graphene/SiC(0001) interface to achieve high carrier mobility. Upon successful Si dangling bonds elimination, carrier mobility increases from 3 000 cm^2/Vs to > 11 000 cm^2/Vs at 0.3 K. Additionally, graphene electron concentration tends to decrease from a few 10^12 cm^-2 to less than 10^12 cm^-2. For a typical large (30x280 um^2) Hall bar, we report the observation of the integer quantum Hall states at 0.3 K with well developed transversal resistance plateaus at Landau level fillings factors of nu = 2, 6, 10, 14.. 42 and Shubnikov de Haas oscillation of the longitudinal resistivity observed from about 1 T. In such a device, the Hall state quantization at nu=2, at 19 T and 0.3 K, can be very robust: the dissipation in electronic transport can stay very low, with the longitudinal resistivity lower than 5 mOhm, for measurement currents as high as 250 uA. This is very promising in the view of an application in metrology.

References in corpus (16)

• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Landau level degeneracy and quantum Hall effect in a graphite bilayer
• Quasi-free Standing Epitaxial Graphene on SiC by Hydrogen Intercalation
• Weak localisation magnetoresistance and valley symmetry in graphene
• Raman spectroscopy of epitaxial graphene on a SiC substrate
• Quantum Resistance Standard Based on Epitaxial Graphene
• SiC Graphene Suitable For Quantum Hall Resistance Metrology
• First direct observation of a nearly ideal graphene band structure
• The quasi-free-standing nature of graphene on H-saturated SiC(0001)
• The Origin of Doping in Quasi-Free Standing Graphene on Silicon Carbide
• Correlating Raman Spectral Signatures with Carrier Mobility in Epitaxial Graphene: A Guide to Achieving High Mobility on the Wafer Scale
• A wide band gap metal-semiconductor-metal nanostructure made entirely from graphene
• How Graphene-like is Epitaxial Graphene? \\Quantum Oscillations and Quantum Hall Effect
• Interplay between interferences and electron-electron interactions in epitaxial graphene
• Effect of Oxygen Adsorption on the Local Properties of Epitaxial Graphene on SiC (0001)
• Observation of the quantum Hall effect in epitaxial graphene on SiC(0001) with oxygen adsorption