4 ms·

With photolithography, what most chips are made with, the resist is developed by exposing it to UV light. A mask is used so that the desired parts of the resis

With photolithography, what most chips are made with, the resist is developed by exposing it to UV light. A mask is used so that the desired parts of the resist are left behind, and the rest is washed away. Contact photolithography places the mask directly against the silicon wafer because it helps the optics during exposure, but the mask doesn't directly remove the resist. In nanoimprint lithograhy, a stamp is pressed into the resist on wafer and leaves the desired pattern behind. The difference is that the resist is removed mechanically instead of chemically.

pests 3y ago
How does the stamp not get damaged or degrade over time? Or is this part a consumable / easily replaced?
- mjevans 3y ago
  It might help you to look up https://en.wikipedia.org/wiki/Mimeograph https://en.wikipedia.org/wiki/Mimeograph and possibly other copying techniques. More approachable examples include CD / DVD https://en.wikipedia.org/wiki/Compact_disc_manufacturing https://en.wikipedia.org/wiki/Compact_disc_manufacturing or earlier vinyl record production methods. For the case of chip lithography they'd probably make source masks, copy the first generation a time or two, and use those secondary source masks to produce consumable 'stamps' for production. Hopefully the stamps maintain sufficient quality across at least a couple batches (50-100+?) of wafers.
  - jacquesm 3y ago
    I highly doubt it will be that much initially. Silicon is pretty hard.
    - phire 3y ago
      The stamp doesn't touch the silicon or any other solid material, it hovers just above. It only touches a liquid photo-resist that is spread on the wafer. The stamp is transparent, which allows UV light to shine though and exposes the photo-resist, which solidifies into a mask matching the stamp.
      - jacquesm 3y ago
        Ah ok! I thought the two were actually in contact. Ok, in that case they might get some life out of them.

pests 3y ago

How does the stamp not get damaged or degrade over time? Or is this part a consumable / easily replaced?

mjevans 3y ago
It might help you to look up https://en.wikipedia.org/wiki/Mimeograph https://en.wikipedia.org/wiki/Mimeograph and possibly other copying techniques. More approachable examples include CD / DVD https://en.wikipedia.org/wiki/Compact_disc_manufacturing https://en.wikipedia.org/wiki/Compact_disc_manufacturing or earlier vinyl record production methods. For the case of chip lithography they'd probably make source masks, copy the first generation a time or two, and use those secondary source masks to produce consumable 'stamps' for production. Hopefully the stamps maintain sufficient quality across at least a couple batches (50-100+?) of wafers.
- jacquesm 3y ago
  I highly doubt it will be that much initially. Silicon is pretty hard.
  - phire 3y ago
    The stamp doesn't touch the silicon or any other solid material, it hovers just above. It only touches a liquid photo-resist that is spread on the wafer. The stamp is transparent, which allows UV light to shine though and exposes the photo-resist, which solidifies into a mask matching the stamp.
    - jacquesm 3y ago
      Ah ok! I thought the two were actually in contact. Ok, in that case they might get some life out of them.