Electronic Devices from Nanopatterned Epitaxial Graphite
Since its advent, graphene, an atomically thin graphite sheet, has been investigated intensively due to its unique electronic properties and ballistic transport. We are currently working on growing 3C-SiC on Si(111) surface, which can be used for graphene growth. Single precursors which are easily decomposed with low temperatures (~ 800°C) are dosed onto a Si wafer in an ultrahigh vacuum (UHV) chamber. On 3C-SiC/Si(111), graphene could be grown by thermal decomposition or dosing chemical precursor with temperature lower than 1200°C.
Graphene Growth
3C-SiC can be used because of its potential application for high powered electronic devices. 3C-SiC(111) is grown on Si(111) surface. At first, the Si(111) wafer is transferred into the UHV chamber. Then, it is heated to remove the silicon dioxide layer to generate a Si(111)-7 7 reconstructed surface. A precursor which has Si and C is dosed onto the Si(111)-7 7 to produce 3C-SiC. Finally, the sample is heated or dosed with polyaromatic hydrocarbon (PAH) to produce epitaxial graphene (EG).
Charaterization
The characterization of this surface is carried out by scanning tunneling microscopy (STM) and Raman scattering spectroscopy. STM study shows not only the atomic structure of the graphene surface, but also its electronic properties. Raman spectra, which have been done for epitaxial graphene grown on 6H-SiC, indicates that the first graphene like layer interacts with the buffer layer created between the EG and the SiC substrate, which causes the suppression of electron - phonon coupling. The presence of the D band at 1360 cm-1 indicates defects are generated during the growth process. This feature is usually absent in Raman spectra of mechanically exfoliated graphene.
References
- Claire Berger et al., Science 2006, 312, 1191
Members on Project
Doogie Oh and Denis Sokolov
Collaborators
- Phillip N. First, School of Physics, Georgia Institute of Technology
- Walter A. de Heer, School of Physics, Georgia Institute of Technology
- Melin Liu, School of Materials Science and Engineering, Georgia Institute of Technology
- James D. Meindl, School of Electrical and Computer Engineering, Georgia Institute of Technology
Funding
National Science Foundation Nanoscience Interdisciplinary Research Team (NIRT)