The role of carbon surface diffusion on the growth of epitaxial graphene on SiC.

Conference · Mon Mar 01 04:00:00 EST 2010

OSTI ID:989977

Thurmer, Konrad ^[1]; Ohta, Taisuke; Nie, Shu ^[1]; Bartelt, Norman Charles ^[1]; Kellogg, Gary Lee

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1. Sandia National Laboratories, Livermore, CA

Growth of high quality graphene films on SiC is regarded as one of the more viable pathways toward graphene-based electronics. Graphitic films form on SiC at elevated temperature because of preferential sublimation of Si. Little is known, however, about the atomistic processes of interrelated SiC decomposition and graphene growth. We have observed the formation of graphene on SiC by Si sublimation in an Ar atmosphere using low energy electron microscopy, scanning tunneling microcopy and atomic force microscopy. This work reveals that the growth mechanism depends strongly on the initial surface morphology, and that carbon diffusion governs the spatial relationship between SiC decomposition and graphene growth. Isolated bilayer SiC steps generate narrow ribbons of graphene, whereas triple bilayer steps allow large graphene sheets to grow by step flow. We demonstrate how graphene quality can be improved by controlling the initial surface morphology specifically by avoiding the instabilities inherent in diffusion-limited growth.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 989977
• Report Number(s): SAND2010-1550C
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON
CRYSTAL GROWTH
DECOMPOSITION
DIFFUSION
EPITAXY
FILMS
GRAPHITE
MORPHOLOGY
PROCESS CONTROL
SILICON
SILICON CARBIDES
SUBLIMATION
SUBSTRATES
SURFACE PROPERTIES