From Ink-Jet Technology to Nano Array Writing Technology

1
From Ink-Jet Technology to Nano Array Writing
Technology

• By
• Szu-kang Hsien
• Ayodeji Coker

2
OVERVIEW

• Objective.
• Approach.
• Our Nano Array Writing Device.
• Conclusion.
• Acknowledgements.

3
OBJECTIVE

• The use of nano-technology and microfabrication
  techniques for nano array writing.
• Replacing conventional lithography methods with
  nano array writing capable of producing 30nm line
  widths.
• The independent control of each AFM tip used in
  the nano-array writing technology using
  comb-drive actuators.

4
APPROACH

• Using the concept employed in Dip Pen
  Nanolithography (DPN) for nano array writing.
• Using ink-jet technology as a mode of delivering
  ink to an AFM tip capable of writing line widths
  on the order of nano-meters.
• Motion control in the x-y-z plane is done using
  comb-drive and electrostatic actuators.

5
INK JET TECHNOLOGY

• Drop On Demand (DOD) ink-jet printing is to be
  utilized in our device.
• A high voltage is to be applied to a PZT crystal
  causing it to bend. This effect in turn applies a
  pressure on the ink reservoir.
• As a result of the applied pressure, the
  reservoir jets out ink on demand, in our case to
  coat the AFM tip.

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Schematic of Ink delivery structure
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INK JET TECHNOLOGY

• A change in voltage gives rise to a corresponding
  change in force and the resulting dimensional
  change in length.
• ?Vdij?Fjx/(?o?rA)
• ?F will be 0.11 N using PZT film dimension
  100?m100?m, er3000, d11370 pC/N, d31110 pC/N,
  V10V and x 2?m.
• The displacement of the crystal, ?L LV/(td31),
  will be around 0.2?m.
• So we can stack around 5 PZT crystals together in
  order to have 1?m pressing into the ink

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DIP-PEN NANOLITHOGRAPHY (DPN)

• Old technique of dip pen writing.
• In place of the nib used in the regular dip-pen,
  an AFM tip is employed.
• Using ink-jet technology, ink is transported to
  the AFM tip, which it coats.
• The ink is delivered to the substrate, by
  choosing an ink and substrate that have an
  affinity for one another e.g ODT and Au.

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ATOMIC FORCE MICROSCOPE (AFM)

• AFM relies on a scanning technique to to produce
  very high resolution 3-D images of sample
  surfaces.
• There are three methods used in AFM applications.
  They are the contact mode, the intermittent
  contact mode and the non contact imaging.
• The method employed NAWT is the intermittent
  contact mode method.

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Force vs. distance curve showing tip sample
Separation of different AFM operating modes.
11
Schematic of AFM
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COMB DRIVE AND ELECTROSTATIC ACTUATORS

• A large number of fine interdigiated fingers are
  actuated by applying a voltage between them.
• This will provide the x-y motion for our device.
• The z-motion is achieved by electrostatically
  actuating the cantilever on which the AFM is
  attached.

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Comb Drive Actuators
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Our Nano Array Writing Device

• Ink Jet Structure.
• Scream Process for the fabrication of the comb
  drive actuators.
• AFM tip fabrication.
• 3-D image of our nano array writing device.

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Ink Jet Fabrication
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Scream Process
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AFM tip Fabrication
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3-D Structure Of Our Device
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Conclusion

• Technology is feasible.
• NAWT is a faster way of doing lithography.
• Comb drive in Collaboration with electrostatic
  cantilever deflection is a good method of control
  in all 3 dimentions.

20
Acknowledgements.

• Prof. Horacio Espinosa for his guidance and
  advice.
• Prof. Chad Mirkin for taking time to provide us
  with all the necessary information on DPN.
• Zhu the TA for all the literature and help he
  gave us.