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Etching and narrowing of graphene from the edges

Nature Chemistry volume 2, pages 661665 (2010) | Download Citation

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.

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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.

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Affiliations

  1. Department of Chemistry and Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA

    • Xinran Wang
    •  & Hongjie Dai

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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.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Hongjie Dai.

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DOI

https://doi.org/10.1038/nchem.719

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