Want even tinier chips? Use a particle accelerator
74 comments
·March 17, 2025hengheng
maxglute
>economically viable
IIRC EUV development picked plasma over synchrotron because plasma projected to be cheaper, even though technically synchrotron had more benefits. Queue many, many years of solving for technical challenges for LPP and now commercialized EUV machines cost 200m, 400m for next high NA. Which is about the cost of multiple small or single medium size synchrotron facility. It's amazing plasma EUV works, but it's also a failure in the sense that it is FAR less economical than originally envisioned, which explains why particle accelerator route is still being worked on.
smallmancontrov
Back in the day, HP advertised that the distributed amplifiers in their 26.5 and 50 GHz equipment were made with e-beams, but the process size wasn't anything special, certainly not by today's standards. I'm not really sure what drove the decision.
artemonster
that tinfoil hat theory, just as basically all of them, can only be produced by people that have absolutely zero understanding of the topic. The amount of challenges that industry has faced during the relatively fast progress through nodes is just non skippable, as there were so many things to be discovered through very expensive and long brute force (just one example: high k dielectrics)
fooker
No, you can absolutely make specialized chips that are orders of magnitude better than the commercial state of the art if you don't care about mass production or operational costs.
I can bet there are superconductor/photonics/topologically different/strange memory/smaller process size prototypes around.
Right now we are getting to the limits of transistor sizes, but even a couple of years ago experimental prototypes of smaller process size were developed years before mass production.
LeifCarrotson
Well sure, at many orders of magnitude more cost. If you wanted to brute-force RSA, you'd be better off leveraging economies of scale to operate ten thousand current-gen 4nm GPUs running at 2 GHz with air coolers than a single exotic prototype 1nm ASIC running at 8 GHz with cryogenic cooling.
Aside from LCS35, most cryptographic problems are about as easy with two processors that are half as fast as one processor that costs twice as much.
almostgotcaught
> No, you can absolutely make specialized chips
proof? i'm just like... where? where do you think people are making these chips and using which ovens?
> smaller process size prototypes around
no there aren't. there just aren't. you could hide this in your basement about as easily as you could hide building your own space shuttle (and launching).
artemonster
where you get this nonsense? I am from semicon industry, so please, sources for the claim "orders of magnitude better"
christkv
Where is my superconductor based CPUs preferably at room temperature.
_carbyau_
Hell, even liquid nitrogen temperatures are fine. More hassle than you'd want in your pocket but yearly running costs wouldn't be too bad for most businesses.
nick3443
Does a superconducting semiconductor even make sense philosophically?
throwaway81523
It's a superconducting switch, not a semiconductor per se. Lookup "Josephson junction". IBM spent a fortune on a huge R&D program to make computers from this, but eventually abandoned it. I think they got some circuitry working but eventually decided it wasn't practical enough to commercialize.
Also, some of today's work in quantum computers uses superconducting qubits. Maybe that's in the same research stage now. No idea if it will ever become practical.
elchananHaas
Free Electron Lasers have potential to generate more tunable radiation with higher luminosity. Despite this they aren't a drop in replacement for the current EUV light sources. A free electron laser is 200 meters long, so a single laser would feed multiple EUV machines for it to be economical. This technology is very promising but it has been under development for a while. Does anyone know what the current difficulties are?
muhdeeb
As far as I understand it, smaller scale XFEL devices still suffer from poor aim, even though now these machines have been miniaturized to basement scales. They don’t need to be significant fractions of a kilometer anymore. This aim issue will probably be solved in the next few years. It’s an exciting time to be in X ray science, particularly anything ultrafast.
sevensor
Headline stuck me funny; I was working in ion implantation 20 years ago. Of course they’re talking about lithography, because those guys are the fighter pilots / first violinists of semiconductor manufacturing, they get all the attention.
mgnn
This article from half a year ago has photos and diagrams https://spectrum.ieee.org/euv-fel
kev009
Is the idea that this will scale? You can already build down to the atomic level with scanning tunneling microscopy (thanks IBM).
adastra22
No, we cannot. IBM moved neutral atoms around on an inert surface. No one has demonstrated building covalent structures (or metallic, or ionic for that matter).
My startup is trying to do this, and it is a fiendishly hard problem.
kev009
Is this "we" you and your startup or all of humanity? There are a variety of published papers that show simple memories and other structures that are way outside my domain knowledge (qd transistors?).
adastra22
No one has ever demonstrated the synthesis of atomically precise structures by positional chemistry.
Quantum dots are not mechanosynthesized, or even atomically precise in many/most instances.
fooker
Why though?
adastra22
Why is it hard? You need to be able to position things with sub-angstrom precision from a platform that has ~nm uncertainty in the critical z positioning, and in the case of nc-AFM is oscillating to boot.
And you can’t use existing tools. You need an atomically precise scanning probe tip with very specific reactive chemical structure, but NOT react with the surface while scanning with a voltage bias.
And where do you source feedstock from? Needs to be delivered to the surface in passive form but be activated when needed to switch to being chemically reactive in a specific way to get it on the transfer tool and then onto the part being built.
Oh, and this is without even getting into how many electronic structures are entirely invisible at certain voltages, everything looks like an identical blobish shape, surfaces are reconfiguring themselves constantly, and probes randomly crash due to piezo creep, destroying days or weeks of work.
My startup has solutions to all of these problems. And the payoff at the end is reliable, scalable quantum computers, followed by full-on Drexlarian nanotech. But yeah, it’s a fiendishly hard problem.
lightedman
Things don't like to move once they're atomically-stuck together. Getting them to stick is another issue altogether. Doing so in reliable locations repeatedly at scale? Good luck.
itishappy
Yes, electron-beam lithography is fantastic but also fantastically slow. Sorta like building a Lego model brick by brick vs layer by layer. It's still used for reticle fabrication and repair.
https://en.wikipedia.org/wiki/Electron-beam_lithography
Edit: Confused SEMs and STMs, but the principle described above applies to both.
sevensor
Where the reticle is worth patterning expensively because it gets used in so many subsequent exposures using light rather than electrons.
gorkish
If you want to make features tinier than EUV allows, you do what you have done for the last few decades and make them directly, but real slow and costly, with electron beams. IMO at some point it seems likely that someone will simply decide to brute force e beam litho up to mass production rates.
anfilt
Direct-write lithography has been a thing for a long time such as EBL. It's just SLOW. So it's only really viable for devices that are made in low quantities, simple devices or research.
sroussey
I was hoping to see table top particle accelerators like those at UCLA were progressing into something usable for lithography. Which makes me wonder, why not use electrons instead of light?
thmsths
From my non expert understanding, we already do kinda. The masks used for photolithography are made using an electron beam, allowing for a much greater resolution than what the underlying photolithography allows. But this is far too slow for large scale production.
Scanning an electron beam, repeatedly over an entire waffer would take forever. So instead we do it once, to make the mask, and that mask is then used over and over to expose the waffer.
This is a bit little injection molding: the mold is very expensive and made with a far better manufacturing process than the plastic pieces that it will eventually produce, but this is the price to pay for high volumes and low costs.
stanleykm
Adding to this, from what I’ve read electron beam is too slow for the required throughput. The ASML EUV machine can etch something like 170 wafers per hour. Using an electron beam would be far too slow for 2-3 wafers per minute.
bobmcnamara
I would like to double check some units.
2-3 wafers per minute would be 120-18 wafers per hour - did you mean wafers per hour for both?
adgjlsfhk1
It would be interesting to see if this tech was viable for dev boards. i.e. when you want to design a new 2nm chip, what if you were using electron beam chips to test out designs?
xeonmc
Ebeam is a pencil, photolithography is a printing press.
avs733
To put rough numbers to this:
1.5B transistors in a current intel core chip
300 die per wafer
150 wafers an hour
That means each litho tool prints 6.75 x 10^13 “transistors” per hour. In more useful units, that’s 18.75B transistors per second.
Drawing them one line at a time is technically feasible but…I’ll bet you are talking single digit DIE per hour if that.
And that is for one layer of lithography. I’ve seen estimates from 5-20 layers of lithography using EUV tools at the 3-7nm nodes. So the time scale is even more warped.
CamperBob2
It might be as simple as the fact that anything the electrons hit will pick up a huge electric charge. Now you've got ESD problems from hell, not to mention unwanted X-ray generation.
gaze
you can use an anti-charging layer for e-beam litho, that's not such a big deal. E-beam litho is just very slow. There are lithography techniques that use synchrotron sources like LIGA.
JimBlackwood
Funny, we asked why they didn’t use a cyclotron during an ASML visit
Things would get a bit radioactive at those energies, though.
russellbeattie
Lead is cheap, right?
Very cool you visited ASML. Anything exciting/interesting you'd be willing to tell the class?
JimBlackwood
Hah, I think there’s two things that stand out in my memory.
- They need 3 Boeing 737’s to ship an EUV machine. - We talked with one guy who’s responsibility it was to design one of the calibration points the machine uses to find it’s zero position. This left me amazed that they’re able to ship a machine halfway across the world, re-assemble it and calibrate it again to such accuracy. And! On top of that, make it reproducible over different machines!
russellbeattie
Oh, I've actually seen that in videos! If you Google it, there's tons of pics showing the loading/unloading. They're not one-offs either. TSMC may order 80 at a time.
Hadn't thought about calibration afterwards. Crazy.
n0n0n4t0r
So they basically want to use synchrotron?
PaulHoule
Hooked up to a free electron laser
https://en.wikipedia.org/wiki/Free-electron_laser
or some similar kind of device that turns the momentum of electrons into light. I'm a little surprised that they didn't try something like a FEL first instead of that terribly problematic device that uses highly inefficient lasers to blow up tin droplets, itself a high-loss process that produces contamination and resulted in years of delay developing materials for
https://www.asml.com/en/news/stories/2022/the-euv-pellicle-i...
monocasa
They tried both in the initial design phase, there's upsides and downsides, but ultimately thought that the tin droplet laser was more liekly to actually get done more or less on the time schedule requested, and so that's where the bulk of the capital went.
Interestingly China has been continuing working on the synchotron based EUV litho idea (in addition to work to create domestically built tin laser EUV lithos machines).
spudnik
[dead]
itishappy
Love me some FELs. Pretty sure they did try this, but determined it to be too large and costly for the technology of the time.
https://www.asianometry.com/p/euv-lithography-but-with-a-fre...
phkahler
My bet is on plasma Wakefield accelerators to feed the FEL. But yeah a synchrotron might do as an intermediate step. Free Electron Lasers can be tuned to different wavelengths all the way to x-rays.
EUV has always been about achieving high enough power to be economically viable. It was never about making chips at any cost.
I remember reading the tinfoil hat theory about three-letter agencies making low-quantity high-cost chips at incredible process sizes in order to break encryption. I doubt that's still as viable today as it was before leakage currents started dominating, but it was an impressively plausible theory.