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The correlation of epitaxial graphene properties and morphology of SiC (0001)

Authors :
R. Yang
Jian Yu Huang
Xuliang Chen
Yanan Guo
Y. P. Jia
Z. L. Li
W. J. Lu
Jingjing Lin
Liwei Guo
Source :
Journal of Applied Physics. 115:043527
Publication Year :
2014
Publisher :
AIP Publishing, 2014.

Abstract

The electronic properties of epitaxial graphene (EG) on SiC (0001) depend sensitively on the surface morphology of SiC substrate. Here, 2–3 layers of graphene were grown on on-axis 6H-SiC with different step densities realized through controlling growth temperature and ambient pressure. We show that epitaxial graphene on SiC (0001) with low step density and straight step edge possesses fewer point defects laying mostly on step edges and higher carrier mobility. A relationship between step density and EG mobility is established. The linear scan of Raman spectra combined with the atomic force microscopy morphology images revealed that the Raman fingerprint peaks are nearly the same on terraces, but shift significantly while cross step edges, suggesting the graphene is not homogeneous in strain and carrier concentration over terraces and step edges of substrates. Thus, control morphology of epitaxial graphene on SiC (0001) is a simple and effective method to pursue optimal route for high quality graphene and will be helpful to prepare wafer sized graphene for device applications.

Details

ISSN :
10897550 and 00218979
Volume :
115
Database :
OpenAIRE
Journal :
Journal of Applied Physics
Accession number :
edsair.doi...........5cb35c738a474968ebca560abea3edc0