Speaker
Mr
Marc González Cuxart
(ICN)
Description
Mechanical exfoliation of highly oriented pyrolytic graphite (HOPG) has been the most
common method of producing single layers of graphene. However, the lateral dimensions of
monolayer samples are typically limited to the micro-scale. Since large area graphene films on
insulating substrates are required for practical applications, several techniques have been
explored such as chemical vapor deposition (CVD) on transition metals, graphitization of SiC
wafers under high vacuum, and reduction of oxidized graphite films.
Plasma Enhanced Chemical Vapor Deposition (PE-CVD) [1-3] makes the deposition method more tunable as it allows for an independent control of the reaction
parameters and the growth parameters, which should lead to a better control of the size and
shape of the nanostructures. Moreover, converting the precursor gas into a plasma state
involves, by definition, a higher amount of active carbon radicals in the reaction process and
thus enhances the deposition rate. By means of using a highly reactive deposition technique
such as a hydrocarbon plasma, one can decrease the exposure time and/or decrease the
substrate temperature. This latter feature opens the deposition process towards a wider variety
of substrates with lower melting points. Last but not least, a remote plasma is – by definition -
generated at a distance from the substrate, thus minimizing preferential perpendicular growth
directions that the electrical fields may induce in a traditional plasma setup.
CELLS-ALBA together with ibss Group, Inc. has adapted the GV10x downstream inductively
coupled RF plasma source typically used for cleaning hydrocarbon contaminated from SEM
chambers to also remove carbon deposits on optical precision surfaces [4]. For these applications
the feedstock gas of the plasma consists of a chemically active agent such as oxygen or
hydrogen converting carbon into CO2, CO, or hydrocarbons gas via a corresponding oxidation
or reduction process, respectively.
References
[1] Y. B. Zhang, Y. W. Tan, H. L. Stormer, and P. Kim. Nature (London) 438, (2005), 201.
[2] T. Otha, A. Bostwick, T. Seyller, and K. Horn, Science 313, (2006), 951.
[3] Gopichand Nandamuri, Sergei Roumimov, and Raj Solanki. App. Phys. Lett. 96, (2010), 154101.
[4] M. González Cuxart and E. Pellegrin, rPECVD of graphene on various substrates, thesis corresponding to the Master in “Nanotechnology and Materials Science”, Universitat Autònoma de Barcelona and ALBA-CELLS (2014).
| Caption (s) - Add figures as attached files (2 fig. max) | Figure 1: SEM image of one of our graphene samples. Figure 2: Raman spectra corresponding to some of our graphene samples. |
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Primary author
Mr
Marc González Cuxart
(ICN)
Co-authors
Dr
Eric Pellegrin
(CELLS-ALBA)
Dr
Igors Sics
(CELLS-ALBA)
