Graphene formation on step-free 4H-SiC(0001)

M. L. Bolen, Birck Nanotechnology Center, Purdue University
R. Colby, Birck Nanotechnology Center, Purdue University
E A. Stach, Birck Nanotechnology Center, Purdue University; Brookhaven National Laboratory
Michael A. Capano, Birck Nanotechnology Center, Purdue University

Date of this Version

10-1-2011

Citation

Journal of Applied Physics: Volume 110, Issue 7

Comments

Copyright (2011) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics: Volume 110, Issue 7 and may be found at http://dx.doi.org/10.1063/1.3644933. The following article has been submitted to/accepted by Journal of Applied Physics. Copyright (2011) M. L. Bolen, R. Colby, E. A. Stach, and M. A. Capano. This article is distributed under a Creative Commons Attribution 3.0 Unported License.

Abstract

Step-free SiC was thermally decomposed in vacuum to better understand graphene formation in the absence of step fronts. Atomic force microscopy revealed graphene nucleating at surface pits that preferentially form along SiC{1 $(1) over bar $ 00} planes. The density of these pits is 1 x 10(8)cm(-2), which is three orders of magnitude greater than the measured density of SiC threading dislocations. Additionally, Raman spectroscopy demonstrated that graphene on step-free regions have a redshifted 2D peak position and a smaller peak width than does graphene grown on stepped regions. This difference is attributed to film thickness, which is confirmed by cross-sectional transmission electron microscopy. Stepped regions have a graphitic film nearly 2 nm thick as compared to less than 0.7 nm for step-free regions. (c) 2011 American Institute of Physics. [doi: 10.1063/1.3644933]

Discipline(s)

Nanoscience and Nanotechnology

 

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