| This interest is strongly motivated by the fascinating and unique electronic and mass transport properties of the graphene, which make it as the new challenging material for the future nanoelectronics devices.  Up to now, two main elaboration methods have been employed to produce graphene layers. The first exploit conventional micromechanical exfoliation of isolated graphene from bulk graphite. However this method appears to be unsuitable for large-scale production of graphene-based devices. Moreover, the poor substrate quality limits the application of this method for high-frequency applications. The later method is based on the epitaxial growth of Few Graphene Layers (FLG) deposited on top of silicon carbide substrate (SiC). This method is up to now the most promising, still need to reduce the expensive coast of an industrial production.
Developing graphene synthesis methods on silicon substrate, compatible with the silicon mass production industries, will enable to drastically reduce the production coast and make the graphene more relevant for future nanoelctronics technologies. In this view, a collaborative team from the CNRS (LPN-Marcoussis, INSP-Paris and CRHEA-Valbonne) and SOLEIL (TEMPO and HERMES beamlines) has developed a new graphene elaboration method (thin SiC layer on Silicon). The originality of this new approach is based on the use of a thin SiC epilayer deposited on Silicon wafers as pseudo-substrate, which allow overcoming the use of expensive SiC substrate. This new method has an important technological impact because it allows to reduce the production coast (up to a factor 10), linking the exceptional graphene properties with Silicon based technologies. Moreover, this method should enable to transpose the technological knowledge gained in Silicon based electronic devices to the graphene.
The recent results obtained by means of Angle Resolved PhotoEmission Spectroscopy (ARPES) on TEMPO beamline at SOLEIL, confirm that the graphene layer obtained following this new method has the similar intrinsic electronic properties as the classical graphene grown on SiC substrate. The CNRS-SOLEIL team has clearly demonstrated the presence of a singularity in the grapheme band structure (DIRAC Cone), which is the electronic signature of graphene layer. Complementary electron transport measurements have confirmed that the graphene elaborated following this new method has similar electronic properties as the classical graphene. Finally, the combination of microscopy techniques (LEEM, STEM, and STM) and the Angle Resolved PhotoEmission Spectroscopy (Figure 1), allow to demonstrate the coherence and the direct correlation between the structural and the electronic properties of the graphene layers (Ref 1 & 2). The graphene surface obtained following this new method has a high crystalline quality with typical domain size one order of magnitude larger than those reported with the classical elaboration methods. These encouraging and promising results, clearly demonstrate that the graphene can be an ideal material for future Silicon and Carbone electronic devices. The ability to grow high quality graphene layer on Silicon substrate will enable to open up new opportunities for semiconductor nanoelectronics technology, making the devices faster, cheaper and more reliable. Contact:
Abdelkarim.ouerghi@lpn.cnrs.fr
Rachid.belkhou@synchrotron-soleil.fr
Fausto.sirotti@synchrotron-soleil.fr
[1] Structural coherency of epitaxial graphene on 3C-SiC(111) epilayers on Si(111); A. Ouerghi, R. Belkhou, M. Marangolo, M. Silly, S. El Moussaoui, M. Eddrief, L.Largeau, M. Portail, and F. Sirotti, APPLIED PHYSICS LETTERS 97, 1 (2010) [2] Epitaxial graphene on 3C-SiC(111) pseudosubstrate: Structural and electronic properties; A. Ouerghi, M. Marangolo, R. Belkhou, S. El Moussaoui, M. G. Silly, M. Eddrief, L. Largeau, M. Portail, B. Fain, and F. Sirotti; PHYSICAL REVIEW B 82, 125445 (2010) | 
Figure 1 : Electronic characterisation of graphene elaborated on SiC/Si pseudosubtrate: band structure dispersion measured using ARPES spectroscopy of one monolayer graphene on Si(111). The band structure clearly evidence close to the Fermi level a DIRAC cone singularity, signature of a 2D graphene layer. 
Figure 2 : Structure and morphology of graphene elaborated on SiC/Si: LEEM images (Low Energy Electron Microscopy) on Dark Field mode of one monolayer graphene on Si(100). The image shows a characteristic domains size of nearly one order magnitude larger than those obtained using classical elaboration methods.
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