Comment by phkahler | Hacker News Reader

Comment by phkahler | Hacker News Reader

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Not sure if Intel has other problems, but there are limits to how small things can get with a particular wavelength of light. DUV (deep ultraviolet) is at 193nm. They've been able to etch significantly smaller than the wavelength by using immersion (water has a higher index of refraction) and some fancy tricks with multiple exposures under different masks (multi-patterning). But all that had to be done because there were no suitable light sources with shorter wavelength. EUV (extreme ultraviolet) has a wavelength of only 13.5nm so a lot of complexity will go away when it comes on line. However EUV still has some challenges ahead and will probably be deployed slowly. Then, shortly after the introduction of EUV, there are other physical limits around 5nm. The lithography end-game is very near.

It's been really amazing to watch this progression for several decades. The end was declared near a number of times but people always found ways to keep going, but I truly believe it's almost over this time.

What about the single atom transistor?

https://en.wikipedia.org/wiki/Single-atom_transistor

A silicon atom is 0.210nm in size. Even if we cannot each single atoms, we have at least another order of magnitude in die shrinks left. Also, given fabrication companies’ marketing, it would not surprise me if we hear about a 0.13nm fabrication process.

Thanks for the elaboration. Is there also a layman's explanation for the what makes 13.5nm lasers harder to etch with than 193nm lasers?

Radiation at 13nm cannot use normal mirrors or lenses for guiding/focusing the beam. The ones we know of reduce the power significantly such that your light source has to be very powerful. Generating this radiation is not easy.

There are no lenses which are transparent at 13.5. This means you have to use mirrors instead, and even that's a challenge. 13.5nm was selected because it can be reflected by special Molybdenum/Silicon mirrors, but even these mirrors only reflect about 70% of the light. This means that for every two mirrors you add to the system, you have to double the brightness of your energy source.

As I understand it, the EUV light is produced by dropping little drops of tin in front of a laser, which turns it into a plasma that emits 13.5nm light. However, tin particles scatter everywhere and eventually damage the collector mirror, so it's hard to make these machines robust.

I also imagine with these high energies and 30% absorption, you have to cool all the mirrors to keep them from deforming, but I'm no expert.

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