| AVS 60th International Symposium and Exhibition | |
| Graphene and Other 2D Materials Focus Topic | Monday Sessions |
| Session GR+EM+NS+PS+SS+TF-MoM |
| Session: | Growth of 2D Materials |
| Presenter: | H. Fukidome, Tohoku University, Japan |
| Authors: | H. Fukidome, Tohoku University, Japan T. Ide, Tohoku University, Japan M. Suemitsu, Tohoku University, Japan Y. Kawai, Tohoku University, Japan T. Ohkouchi, JASRI/SPring-8, Japan M. Kotsugi, JASRI/SPring-8, Japan T. Kinoshita, JASRI/SPring-8, Japan T. Shinohara, University of Tokyo, Japan N. Nagamura, University of Tokyo, Japan S. Toyoda, University of Tokyo, Japan K. Horiba, University of Tokyo, Japan M. Oshima, University of Tokyo, Japan |
| Correspondent: | Click to Email |
Graphene is the promising material for the next-generation devices due to its excellent electronic properties. We have developed epitaxy of graphene on SiC thin films on Si substrates (GOS) toward fusion of graphene with Si-based electronics. We have found that structural and electronic properties of graphene are tuned by crystallographic orientation of the Si substrates [1,2]. This result indicates that, in combination with Si microfabrication technologies, the electronic properties of GOS may be tuned by microfaceting Si surface [3].
A Si(100) substrate was fabricated by combining electron-beam lithography [3] and alkaline etching which produces (111) and (100) microfacet on the Si(100) substrate. On the microfabricated Si(100) substrate, SiC thin films were grown by using gas-source MBE, followed by graphitization in vacuum at 1500 K. Microscopic characterization of graphene was performed by using 3D NanoESCA for microscopic XPS (micro-XPS) and low-energy electron microscope for microscopic low-energy election diffraction (micro-LEED). Vibrational and bandstructure characterization was done by Raman microspectroscopy.
The micro-LEED observation reveals that graphene is Bernal stacked on the SiC(111)/Si(111) facet, while it is non-Bernal stacked on the SiC(100)/Si(100) microfacet. The observation is in consistent with the previous result on the epitaxy of graphene on non-fabricated SiC(111)/Si(111) and SiC(100)/Si(100) [1, 2]. The variation of the stacking is explained by the micro-XPS observation. The buffer layer which works as a template for the epitaxy of graphene exists only in between graphene and the SiC(111)/Si(111) microfacet. The existence of the buffer layer is also confirmed by cross-sectional transmission electron microscopy observations. Furthermore, Raman microscopy reveals that the band dispersion (splitting) microscopically changes depending on the variation of the stacking with the microfacet.
Our work can open a new way to microscopically tune control of electronic properties of graphene, semiconductive or metallic, which can make graphene devices multi-functionalized on Si substrates.
One of the authors (H. F.) acknowledges a financial support by KAKENHI (23560003).
References: [1] H. Fukidome et al., J. Mater. Chem. 21 (2011) 17242. [2] H. Fukidome et al., Appl. Phys. Exp. 4 (2011) 115104. [3] H. Fukidome et al., Jpn. J. Appl. Phys. 51 (2012) 06FD02.