Wide-range temperature dependence of epitaxial graphene growth on 4H-SiC (0 0 0 −1): A study of ridge structures formation dynamics associated with temperature
✍ Scribed by Shoji Ushio; Arata Yoshii; Naoto Tamai; Noboru Ohtani; Tadaaki Kaneko
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 907 KB
- Volume
- 318
- Category
- Article
- ISSN
- 0022-0248
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✦ Synopsis
We investigated the temperature dependence (1200-2100 1C) of morphological features in the growth of epitaxial graphene on 4H-SiC (0 0 0 À 1) C-face in ultra high vacuum (UHV). As a SiC initial surface preparation technique prior to the epitaxial graphene growth, Si-vapor etching was conducted to ensure a uniform step-terrace structure at 4H-SiC (0 0 0 À 1) consisting of 0.5 nm step height. The epitaxial graphene growth has been performed in our original experimental setup with a TaC container inside an all metal chamber with radiative heating system, which allows to increase the graphitization temperature up to 2100 1C in UHV. The surface morphology of the epitaxially grown multilayer graphene, characterized by atomic force microscopy (AFM), exhibited a drastic change as a function of temperature. Ridge structures of the topmost graphene layer(s) appeared above 1600 1C, where the well-ordered step-terrace initial structure of the SiC vanished. In this high temperature range, the network of the ridges spread over the surface with an increase in temperature. Raman topography mapping for characterizing site dependent 2D-spectrum implies that rotational stacking disorder of graphene layers is accompanied by relatively small ridge network on the surface in a specific temperature range.