It's definitely an "on the shoulders of giants standing on the shoulders of giants" thing. Insane breakthrough technologies on top of other insane breakthroughs. Firing lasers at microscopic molten drops of metal in a controlled enough manner to get massively consistent results like what??
It’s a mind blowing achievement, nothing below sorcery if you think about it.
ASML machines are hitting tin droplets with 25kW laser 50,000 times a second to turn them into plasma to create the necessary extreme ultraviolet light, and despite generating 500W of EUV, only a small fraction can reach the wafer, due to loses along the way. I believe it was like 10%.
One thing I am curious about - how many generations of process shrink is one of these machines good for? They talk about regular EUV and then High-NA EUV for finer processes, but presumably each machine works for multiple generations of process shrink? If so, what needs to be adjusted to move to a finer generation of lithography and how is it done? Does ASML come in and upgrade the machine for the next process generation, or does it come out of the box already able to deliver to a resolution a few steps beyond the current state of the art?
If you’re interested in this stuff Asianometry has lots of great videos. They’re not all on semiconductors, but he’s done a lot on this history, developments, and what’s going on in that world.
Maybe the high water usage is at some other stage? Or intermediate preceding stages? I'd love to understand more end-to-end, as surely it isn't as easy as popping a wafer in a semi-truck trailer sized lithography machine.
Check out the Branch Education channel, they have a series of videos that explain how the underlying transistors are made in 3d space with multilayer exposures etc.
One thing to understand is that you’re seeing an accumulation of over 50 years of incredible engineering and cutting edge science, these things were invented incrementally.
Lithography is one of many steps, but probably the most important one. You use it to expose a photoresist to create a mask for further processing. After exposing the photoresist you need to develop it, remove either the exposed or unexposed photoresist. The remaining photoresist then is the mask and you either etch or dope the surface that is not covered by the mask or you deposit material on top. And then you need to remove the mask and start all over again for the next layer. The high water usage comes from repeatedly needing to clean the surface to remove chemicals and photoresist.
I think this clockwork-in-a-vacuum was preceded by eidophors: a projector with a spinning disc of oil that has an image drawn by an electron gun, that is then illuminated by an arc lamp.
