Challenges to graphene growth on SiC(000(1)over-bar): Substrate effects, hydrogen etching and growth ambient
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2014 Elsevier Ltd. All rights reserved. Controlling the uniformity and morphology of graphene grown on the C-face of SiC is more difficult than on the Si-face. To improve graphene grown on the C-face, a continuous growth process was developed in a conventional tube furnace that included in situ surface preparation by annealing in H2 followed by an Ar-mediated growth, which was done at a variety of different temperatures and pressures. Optimized H2 etch conditions for the C-face were developed to improve the starting substrate morphology and reduce the effect of substrate defects on growth. The resulting graphene film, however, had non-uniform thickness due to intrinsic bulk defects within the SiC substrate and an interfacial oxide. Differences between substrate properties, such as polytype, are shown to have a significant effect on growth, with a 4H substrate displaying faster in-plane graphene growth than a 6H substrate. A primarily 2-domain graphene film with significant rotational disorder was found regardless of the starting substrate and growth conditions. Ultra-high vacuum desorption of the interfacial oxide caused the graphene to reorder into a single preferred rotational orientation, suggesting trace oxygen impurities in the growth chamber can play an important role in graphene growth on the C-face of SiC.
author list (cited authors)
Robinson, Z. R., Jernigan, G. G., Currie, M., Hite, J. K., Bussmann, K. M., Nyakiti, L. O., ... Gaskill, D. K.
complete list of authors
Robinson, Zachary R||Jernigan, Glenn G||Currie, Marc||Hite, Jennifer K||Bussmann, Konrad M||Nyakiti, Luke O||Garces, Nelson Y||Nath, Anindya||Rao, Mulpuri V||Wheeler, Virginia D||Myers-Ward, Rachael L||Wollmershauser, James A||Feigelson, Boris N||Eddy, Charles R||Gaskill, D Kurt