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Progress on Graphite Nanostructures:

Progress on Graphite Nanostructures:. Attempting to approach geometries of interest to theorists. Tom Weller, Steve Bennington (ISIS) Derek Jenkins, Bob Stevens (CMF RAL). Oxygen Plasma Etching. PECVD 200nm SiO 2 onto HOPG (IPE-1000). Spin Coat Photoresist (positive Shipley 1813).

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Progress on Graphite Nanostructures:

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  1. Progress on Graphite Nanostructures: Attempting to approach geometries of interest to theorists Tom Weller, Steve Bennington (ISIS) Derek Jenkins, Bob Stevens (CMF RAL)

  2. Oxygen Plasma Etching

  3. PECVD 200nm SiO2 onto HOPG (IPE-1000) Spin Coat Photoresist (positive Shipley 1813) Proximity Photolithography (GCA 6300 DSW Projection Mask Aligner, 5 x g-line Stepper) HF solution to remove SiO2 not protected by photoresist Remove photoresist (remover Shipley 1165) Oxygen Plasma Etch (Electron Cyclotron Resonance Plasma Quest 357)

  4. Simplified version of Ruoff et al. Spin Coat Photoresist (negative and positive ) UV Pattern Remove Unexposed Photoresist ICP Oxygen Etch (STS)

  5. Ruoff et al. plasma parameters and outcome

  6. Is it possible to etch structures on HOPG with ICP? Ruoff parameters replicable with ICP. Except: minimum pressure achievable was 20mT. Parameters covered: Pressures of 20mT, up to 80mT. Etch times from 1 to 10 minutes. Oxygen flow rates 20 sccm, up to 80 sccm. No HOPG etching on the scales achieved by Ruoff.

  7. Electron Cyclotron Resonance vs. Inductively Coupled Plasma Oxygen pressure is the key, the ECR confines the electrons and lengthens the mean free path, allowing oxygen atoms to achieve higher energies… In process of acquiring ECR source…

  8. SU8 Pyrolisation • SU8 25 spin coated onto Si wafers with a range of thicknesses • Baked at 1000ºC

  9. Spin Coat Photoresist (SU8, and others various thicknesses) Ebeam Pattern (VB6), also try AFM CAFM Nanopatterning Remove Unexposed Photoresist Pyrolise Pyrolise

  10. Pyrolisation of SU8 Initial pressure: 2.8x10-5 mbar. Heating at 20ºC/min • Requirement for gas overpressure in initial stages? • Requirement for slower heating rate?

  11. Pyrolisation of SU8 • Unpyrolised SU8 is amorphous. • Subsequent to pyrolisation a peak forms at ~25.2º, which is equivalent to 3.5Å. • No apparent dependence on thickness.

  12. Graphitise nanostructures? • Need these temperatures for certain graphitisation. Pyrolisation of SU8

  13. Acquiring Furnace capable of 3000°C. • Acquiring ECR plasma source. • Continuing with synthesis techniques. • Aiming toward structures of interest to our theoretical partners.

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