Abstract
Large-scale graphene electronics requires lithographic patterning of narrow graphene nanoribbons for device integration. However, conventional lithography can only reliably pattern ~20-nm-wide GNR arrays limited by lithography resolution, while sub-5-nm GNRs are desirable for high on/off ratio field-effect transistors at room temperature. Here, we devised a gas phase chemical approach to etch graphene from the edges without damaging its basal plane. The reaction involved high temperature oxidation of graphene in a slightly reducing environment in the presence of ammonia to afford controlled etch rate (≲1 nm min−1). We fabricated ~20–30-nm-wide graphene nanoribbon arrays lithographically, and used the gas phase etching chemistry to narrow the ribbons down to <10 nm. For the first time, a high on/off ratio up to ~104 was achieved at room temperature for field-effect transistors built with sub-5-nm-wide graphene nanoribbon semiconductors derived from lithographic patterning and narrowing. Our controlled etching method opens up a chemical way to control the size of various graphene nano-structures beyond the capability of top-down lithography.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Geim, A. K. & Novoselov, K. S. The rise of graphene. Nature Mater. 6, 183–191 (2007).
Geim, A. K. Graphene: status and prospects. Science 324, 1530–1534 (2009).
Li, X., Wang, X., Zhang, L., Lee, S. & Dai, H. Chemically derived, ultrasmooth graphene nanoribbon semidonductors. Science 319, 1229–1232 (2008).
Wang, X. et al. Room-temperature all-semiconducting sub-10-nm graphene nanoribbon field-effect transistors. Phys. Rev. Lett. 100, 206803 (2008).
Jiao, L., Zhang, L., Wang, X., Diankov, G. & Dai, H. Narrow graphene nanoribbons from carbon nanotubes. Nature 458, 877–880 (2009).
Bai, J., Duan, X. & Huang, Y. Rational fabrication of graphene nanoribbons using a nanowire etching mask. Nano Lett. 9, 2083–2087 (2009).
Han, M. Y., Ozyilmaz, B., Zhang, Y. & Kim, P. Energy bandgap engineering of graphene nanoribbons. Phys. Rev. Lett. 98, 206805 (2007).
Chen, Z., Lin, Y.-M., Rooks, M. J. & Avouris, P. Graphene nano-ribbon electronics. Physica E 40, 228–232 (2007).
Pomomarenko, L. A. et al. Chaotic Dirac billiard in graphene quantum dots. Science 320, 356–358 (2008).
Kosynkin, D. V. et al. Longitudinal unzipping of carbon nanotubes to form graphene nanoribbons. Nature 458, 872–876 (2009).
Nakada, K., Fujita, M., Dresselhaus, G. & Dresselhaus, M. S. Edge state in graphene ribbons: nanometer size effect and edge shape dependence. Phys. Rev. B 54, 017954–017961 (1996).
Son, Y.-W., Cohen, M. L. & Louie, S. G. Energy gaps in graphene nanoribbons. Phys. Rev. Lett. 97, 216803 (2006).
Barone, V., Hod, O. & Scuseria, G. E. Electronic structure and stability of semiconducting graphene nanoribbons. Nano Lett. 6, 2748–2754 (2006).
Wang, X., Tabakman, S. M. & Dai, H. Atomic layer deposition of metal oxides on pristine and functionalized graphene. J. Am. Chem. Soc. 130, 8152–8153 (2008).
Lee, S. M., Lee, Y. H., Hwang, Y. G., Hahn, J. R. & Kang, H. Defected-induced oxidation of graphite. Phys. Rev. Lett. 82, 217–220 (1999).
Hahn, J. R., Kang, H., Lee, S. M. & Lee, Y. H. Mechanistic study of defect-induced oxidation of graphite. J. Phys. Chem. B 103, 9944–9951 (1999).
Ni, Z. H. et al. Uniaxial strain on graphene: Raman spectroscopy study and bandgap opening. ACS Nano 2, 2301–2305 (2008).
Mohiuddin, T. M. G. et al. Uniaxial strain in graphene by Raman spectroscopy: G peak splitting, Gruneisen parameters and sample orientation. Phys. Rev. B 79, 205433 (2009).
Li, X. et al. Simultaneous nitrogen-doping and reduction of graphene oxide. J. Am. Chem. Soc. 131, 15939–15944 (2009).
Yan, Q. et al. Intrinsic current−voltage characteristics of graphene nanoribbon transistors and effect of edge doping. Nano Lett. 7, 1469–1473 (2007).
OuYang, F., Xiao, J., Guo, R., Zhang, H. & Xu, H. Transport properties of T-shaped and cross junctions based on graphene nanoribbons. Nanotechnology 20, 055202 (2009).
Ferrari, A. C. Raman spectroscopy of graphene and graphite: disorder, electron-phonon coupling, doping and nonadiabatic effects. Solid State Commun. 143, 47–57 (2007).
Wang, X. et al. N-doping of graphene through electrothermal reactions with ammonia. Science 324, 768–771 (2009).
Zhao, P., Choudhury, M., Mohanram, K. & Guo, J. Computational model of edge effects in graphene nanoribbon transistors. Nano Res. 1, 395–402 (2008).
Yoon, Y. & Guo, J. Effect of edge roughness in graphene nanoribbon transistors. Appl. Phys. Lett. 91, 073103 (2007).
Cresti, A. et al. Charge transport in disordered graphene-based low dimensional materials. Nano Res. 1, 361–394 (2008).
Ci, L. et al. Controlled nanocutting of graphene. Nano Res. 1, 116–122 (2008).
Campos, L. C., Manfrinato, V. R., Sanchez-Yamagishi, J. D., Kong, J. & Jarillo-Herrero, P. Anisotropic etching and nanoribbon formation in single-layer graphene. Nano Lett. 9, 2600–2604 (2009).
Datta, S. S., Strachan, D. R., Khamis, S. M. & Johnson, A. T. C. Crystallographic etching of few-layer graphene. Nano Lett. 8, 1912–1915 (2008).
Nemes-Incze, P., Magda, G., Kamaras, K. & Biro, L. P. Crystallographically selective nanopatterning of graphene on SiO2 . Nano Res. 3, 110–116 (2010).
Novoselov, K. S. et al. Electric field effect in atomically thin carbon films. Science 306, 666–669 (2004).
Hu, W., Sarveswaran, K., Lieberman, M. & Bernstein, G. H. Sub-10-nm electron beam lithography using cold development of poly(methylmethacrylate). J. Vac. Sci. Technol. B 22, 1711–1716 (2004).
Acknowledgements
This work was supported by Intel, the MARCO MSD Center and Graphene MURI (the Office of Naval Research). The authors are grateful to J.W. Conway from the Stanford Nanofabrication Facility for helpful discussions.
Author information
Authors and Affiliations
Contributions
X.W. and H.D. conceived and designed the experiments. X.W. performed the experiments and analysed the data. X.W. and H.D. co-wrote the paper. Both authors discussed the results and commented on the manuscript.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary information
Supplementary information (PDF 2890 kb)
Rights and permissions
About this article
Cite this article
Wang, X., Dai, H. Etching and narrowing of graphene from the edges. Nature Chem 2, 661–665 (2010). https://doi.org/10.1038/nchem.719
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nchem.719