Ultra-low Surface Roughness Polishing

  • MRF generally maintains or improves surface roughness
    • Minimum roughness obtained with MRF typically 3-5 Å
    • Results depend on substrate material and MR fluid used
  • Several key applications require significantly smoother surfaces, even below 1 Å:
    • EUV lithography, high-power laser optics, X-ray mirrors
  • Conventional polishing methods (pitch or synthetic pads) can sometimes achieve lower surface roughness
    (< 2 Å)
    • Requires highly specialized process
    • Typically limited to plano surfaces
    • Low yields due to unpredictability of process, resulting in high costs

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