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Title: Step-edge-induced resistance anisotropy in quasi-free-standing bilayer chemical vapor deposition graphene on SiC

The transport properties of quasi-free-standing (QFS) bilayer graphene on SiC depend on a range of scattering mechanisms. Most of them are isotropic in nature. However, the SiC substrate morphology marked by a distinctive pattern of the terraces gives rise to an anisotropy in graphene's sheet resistance, which may be considered an additional scattering mechanism. At a technological level, the growth-preceding in situ etching of the SiC surface promotes step bunching which results in macro steps ~10 nm in height. In this report, we study the qualitative and quantitative effects of SiC steps edges on the resistance of epitaxial graphene grown by chemical vapor deposition. We experimentally determine the value of step edge resistivity in hydrogen-intercalated QFS-bilayer graphene to be ~190 Ωμm for step height hS = 10 nm and provide proof that it cannot originate from mechanical deformation of graphene but is likely to arise from lowered carrier concentration in the step area. Our results are confronted with the previously reported values of the step edge resistivity in monolayer graphene over SiC atomic steps. In our analysis, we focus on large-scale, statistical properties to foster the scalable technology of industrial graphene for electronics and sensor applications.
Authors:
 [1] ;  [2] ; ;  [3] ; ; ; ;  [1] ;  [1] ;  [2] ;  [4]
  1. Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland)
  2. (Poland)
  3. Department of Electrical and Electronics Engineering, Department of Physics, Nanotechnology Research Center, Bilkent University, 06800 Bilkent, Ankara (Turkey)
  4. Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland)
Publication Date:
OSTI Identifier:
22305706
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; CARRIERS; CHEMICAL VAPOR DEPOSITION; CLATHRATES; CONCENTRATION RATIO; CRYSTAL GROWTH; DEFORMATION; EPITAXY; GRAPHENE; LAYERS; SCATTERING; SENSORS; SILICON CARBIDES; SUBSTRATES; SURFACES