What were the challenges you were seeing or heard were the biggest? The light source?

Everything was a challenge with EUV—the source, the vacuum, the mirrors, the reflective reticle, getting sufficient throughput…

You could write a litany of sorrows just on the mirrors! You have to replace everything with mirrors. Collimation optics, lenses, the damn mask, throwing away decades of work and starting again! All in awful conditions (hard vacuum, every surface in the container slowly being coated in vaporized tin, when they're not being destroyed by EUV light itself...)

Hell, people complain about Moore's Law being delayed by EUV, in any other field it would have taken a decade to switch!

If they gave out Nobels for industrial science, ASML would have a dozen already. Rather reminds me of The Soul of a New Machine... long nights, impossible odds, heroic effort to solve unsolvable problems, all rewarded with a $50 bonus and being told to move onto the next task.

There were years of hope in the semiconductor industry that somebody would come up with something better rather than having to make that nightmare work.

Alternatives were tried. Synchrotron EUV sources. (works, but huge). Linear accelerators (The SLAC beamline was used as a light source as a test). X-ray lasers (don't work yet). Electron beam lithography (works, but too slow.)

There's got to be a better way to do this.

At Imec I recall electron beam lithography was investigated but just too slow. E-beam was analogous to an inkjet printer.

Whatever happened to Multibeam? [1] They claim to sell a multiple electron beam writer for maskless chip making. They, and their predecessor company, have been at this since 1980. Not much new on the web site, and their last press release was in 2020.

EUV masks are made that way, slowly.

[1] https://multibeamcorp.com/

Friend of mine worked for an asml supplier. He was working on adjusting the optical path based on how the laser going through a lens heats that lens up and changes its optical qualities. There are so many challenges we don't even think about

Building a modern semiconductor factory starts long before you can begin to think about the foundation. Minimizing vibration is included in thinking about the siting, seismic insulation of the building and the placement of just about everything in the fab itself.

Think 'boxes in boxes' to get maximum insulation. I also have a friend who works in this industry and he once joked that they have an almanac built in to deal with moon tides and while it is a funny joke you have to wonder if there isn't going to be a time when even that sort of effect will have to be accounted for. Amazing stuff.

ASML is one of a short list of Dutch companies that I'm super proud of, they keep on innovating no matter how extreme the challenges are. The moat they have is incredibly deep.

FWIW, a lot of the underlying technology came from Cymer, which the acquired.

https://www.asml.com/en/company/about-asml/cymer

When you go to the extremes those tiny details suddenly aren't tiny details anymore. As a semi-random example, a significant source of noise in LIGO, the gravitational wave detectors, is the push of photons striking the 40kg mirrors[1][2].

[1]: https://arstechnica.com/science/2020/07/ligo-is-so-sensitive...

[2]: https://arxiv.org/abs/2002.01519