Alloy Thin Films by Multi-Target Sputtering

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Alloy Thin Films by Multi-Target Sputtering

• Karla L. Perez
• MSE/REU
• Final Presentation
• Adv. Prof. King and Prof. Dayananda
• August 5, 2004

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Overview

• Introduction
• Research Project
• Processing
• Measuring Film Thickness
• Optical Microscope
• AFM
• Alloy Thin Film Deposition
• Composition
• Conclusion

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Application of Thin Films

• Antireflection coatings for camera lenses
• Optical filters for communication
• Decorative coatings on plastics
• Silicon chips
• Metallic coatings
• To provide insulating layers between conductors

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Research Project

• The main goal is to create alloy thin films with
  uniform composition and thickness
• Study the compositions of pure metal thin films
  and their thickness
• Pure metal components to be used Ag, Cu, Ta, Mo,
  Ni, Fe, Ti
• Design a system which will enable us to manage
  the composition and geometry of the alloy thin
  films

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Processing

• Sputtering
• It is a type of Physical Vapor Deposition. It is
  carried out at high vacuum in a chamber connected
  to a high voltage DC supply.
• Argon gas is pumped into the chamber and creates
  argon plasma. The Argon plasma is directed to the
  target and its atoms are vaporized. The vaporized
  material is then deposited on the substrate.

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Measuring Film Thickness

• Optical Microscope
• Differential Interference Contrast (DIC)

Ag 20min 4cm
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Measuring Film ThicknessOptical Microscope
Cu 10min 4cm
Ag 20min 4cm
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Measuring Film ThicknessOptical Microscope
Ag 10 min 4cm
Ag 20min 4cm
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Measuring Film Thickness

• Atomic Force Microscope (AFM)
• Tapping mode Measures the topography by tapping
  the surface with an oscillating tip. This
  eliminates the shear forces which can damage soft
  samples and reduce image resolution.

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Measuring Film Thickness
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Measuring Film ThicknessAFM
Ag 20min 2cm
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Measuring Film ThicknessAFM
Mo 30min 2cm
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Measuring Film ThicknessAFM
Cu 30min 2cm
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Ag 30min 2cm
52.40
14.19
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Alloy Thin Film Deposition

• Deposit alloy thin films using a sputter coater
  with a Copper-Silver target

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Composition of Ag-Cu Thin Film
92.7
50.3
7.3
Position on slide
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Composition of Ag-Cu Thin Film
95.6
50.3
4.4
Position on slide
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Conclusion

• The thickness of the film varies according to
  their position relative to the target.
• Films deposited are thicker in the middle.
• Deposited one alloy thin film
• The same composition gradients of silver and
  copper do not occur in the middle of the film.

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Acknowledgements

• Prof. King
• Prof. Dayananda
• Prof. Kvam
• NSF Grant

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Questions???

• Thank you!!!