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Can someone please tell me how photo-masks are produced? I don't understand how can tiny features be printed at almost the same scale as a final structure? With

Can someone please tell me how photo-masks are produced? I don't understand how can tiny features be printed at almost the same scale as a final structure? With a laser beam? Say, as an input you have a layer description (schematics) - how can you transfer it to a tiny scale so precisely to produce a mask?

ArchD 6y ago
Lenses are used so the feature size on the mask is larger than the feature size on the wafer. https://www.nikon.com/about/technology/product/semiconductor/index.htm https://www.nikon.com/about/technology/product/semiconductor...
- novaRom 6y ago
  Yes, but only few times. Still not clear how an initial mask has been produced? From file to mask - a kind of printer or a laser?
  - baybal2 6y ago
    for >1 micron it's optical lithographic transfer, for <1 micron, it's e-beam lithography.
rwmj 6y ago
Photographic reduction. The masks are much larger than the final chips. https://commons.wikimedia.org/wiki/File:Semiconductor_photomask.jpg https://commons.wikimedia.org/wiki/File:Semiconductor_photom... (Actually AIUI in EUV photolithography you can't use transparent masks, but must use a kind of mirror with the pattern etched onto it.)
- novaRom 6y ago
  According to Wikipedia masks are only 4 times larger - it is still very tiny.
ric2b 6y ago
They aren't built at the same scale, they're much larger than the final structure and lenses are used to scale the image down to the desired size. Here's a video form Intel on how they are made: https://youtu.be/u3ws0UebnSE https://youtu.be/u3ws0UebnSE Apparently they use "electron beams", not sure what those are, they sound similar to lasers but with electrons, from this video: https://youtu.be/PWV9pvdRBNY https://youtu.be/PWV9pvdRBNY
- asgeir 6y ago
  Wouldn't that just be something like CRT? https://en.wikipedia.org/wiki/Cathode-ray_tube https://en.wikipedia.org/wiki/Cathode-ray_tube
  - imtringued 6y ago
    It's probably closer to how an electron microscope works.
- novaRom 6y ago
  Wow, this explains why production of a mask takes 5 days (as said in first video): https://en.wikipedia.org/wiki/Electron-beam_lithography https://en.wikipedia.org/wiki/Electron-beam_lithography
- jcun4128 6y ago
  This was also a cool video I saw recently about lithography with plasma lasers https://www.youtube.com/watch?v=f0gMdGrVteI https://www.youtube.com/watch?v=f0gMdGrVteI around 7:14 in particular

ArchD 6y ago

Lenses are used so the feature size on the mask is larger than the feature size on the wafer. https://www.nikon.com/about/technology/product/semiconductor/index.htm https://www.nikon.com/about/technology/product/semiconductor...

novaRom 6y ago
Yes, but only few times. Still not clear how an initial mask has been produced? From file to mask - a kind of printer or a laser?
- baybal2 6y ago
  for >1 micron it's optical lithographic transfer, for <1 micron, it's e-beam lithography.

rwmj 6y ago

Photographic reduction. The masks are much larger than the final chips. https://commons.wikimedia.org/wiki/File:Semiconductor_photomask.jpg https://commons.wikimedia.org/wiki/File:Semiconductor_photom... (Actually AIUI in EUV photolithography you can't use transparent masks, but must use a kind of mirror with the pattern etched onto it.)

novaRom 6y ago
According to Wikipedia masks are only 4 times larger - it is still very tiny.

ric2b 6y ago

They aren't built at the same scale, they're much larger than the final structure and lenses are used to scale the image down to the desired size. Here's a video form Intel on how they are made: https://youtu.be/u3ws0UebnSE https://youtu.be/u3ws0UebnSE Apparently they use "electron beams", not sure what those are, they sound similar to lasers but with electrons, from this video: https://youtu.be/PWV9pvdRBNY https://youtu.be/PWV9pvdRBNY

asgeir 6y ago
Wouldn't that just be something like CRT? https://en.wikipedia.org/wiki/Cathode-ray_tube https://en.wikipedia.org/wiki/Cathode-ray_tube
- imtringued 6y ago
  It's probably closer to how an electron microscope works.
novaRom 6y ago
Wow, this explains why production of a mask takes 5 days (as said in first video): https://en.wikipedia.org/wiki/Electron-beam_lithography https://en.wikipedia.org/wiki/Electron-beam_lithography
jcun4128 6y ago
This was also a cool video I saw recently about lithography with plasma lasers https://www.youtube.com/watch?v=f0gMdGrVteI https://www.youtube.com/watch?v=f0gMdGrVteI around 7:14 in particular