Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (12): 2953-2959.doi: 10.3866/PKU.WHXB20112953

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Direct Graphene Growth by Depositing Carbon Atoms on Si Substrate Covered by SiC Buffer Layers

TANG Jun1,2, KANG Chao-Yang1, LI Li-Min1, XU Peng-Shou1   

  1. 1. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China;
    2. Hefei IRICO Epilight Technology Co., Ltd., Hefei 230011, P. R. China
  • Received:2011-07-13 Revised:2011-10-12 Published:2011-11-25
  • Contact: XU Peng-Shou E-mail:psxu@ustc.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50872128).

Abstract: Graphene is a newly discovered material with many functions. The preparation of graphene on suitable substrates is a challenge in the material preparation field. In this paper, graphene thin films were grown on Si substrates covered with SiC buffer layers (SiC/Si) by the direct deposition of carbon atoms using molecular beam epitaxy (MBE) equipment. The structural properties of the samples produced at different substrate temperatures (800, 900, 1000, 1100 ° C) were investigated by reflection high energy electron diffraction (RHEED), Raman spectroscopy and near-edge X-ray absorption fine structure (NEXAFS). The results indicate that the thin films grown at all temperatures exhibit the characteristics of graphene with a turbostratic stacking structure. As the substrate temperature increases the crystalline quality of the graphene improves. However, a very high temperature decreases the quality of graphene. The best graphene films were obtained at a substrate temperature of 1000 ° C. This is due to the low substrate temperature resulting in a too low carbon atom activity for the formation of an ordered six-member ring of C-sp2. When the substrate temperature was too high the silicon atoms in the substrate became so active that silicon atoms diffused to the surface of the sample through SiC buffer defects and they bonded to the depositing carbon atoms, which resulted in a lower crystallization quality of the carbon layers.

Key words: Graphene, Molecular beam epitaxy, Si substrate, SiC, Synchrotron radiation

MSC2000: 

  • O641