title: Maskless Lithography and in situ Visualization of Conductivity of Graphene using Helium Ion Microscopy.
abstract: The remarkable mechanical and electronic properties of graphene make it an ideal candidate for next generation nanoelectronics. With the recent development of commercial-level single-crystal graphene layers, the potential for manufacturing household graphene-based devices has improved, but significant challenges still remain with regards to patterning the graphene into devices. In the case of graphene supported on a substrate, traditional nanofabrication techniques such as e-beam lithography (EBL) are often used in fabricating graphene nanoribbons but the multi-step processes they require can result in contamination of the graphene with resists and solvents. In this letter, we report the utility of scanning helium ion lithography for fabricating functional graphene nanoconductors that are supported directly on a silicon dioxide layer, and we measure the minimum feature size achievable due to limitations imposed by thermal fluctuations and ion scattering during the milling process. Further we demonstrate that ion beams, due to their positive charging nature, may be used to observe and test the conductivity of graphene-based nanoelectronic devices in situ.
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Vighter
authors.initials: V
authors.lastname: Iberi
authors.affiliation: Energy and Transportation Science, Oak Ridge National Laboratory, Oak Ridge, TN 37831.
authors.forename: Ivan
authors.initials: I
authors.lastname: Vlassiouk
authors.affiliation: 1] Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA [2] Department of Physics and Quantum Theory Project, University of Florida, Gainesville, FL 32611.
authors.forename: X-G
authors.initials: XG
authors.lastname: Zhang
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Brad
authors.initials: B
authors.lastname: Matola
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Linn
authors.affiliation: 1] Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA [2] Department of Materials Science &Engineering, University of Tennessee Knoxville, TN 37996.
authors.forename: David C
authors.initials: DC
authors.lastname: Joy
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Rondinone