thanks for the HN community - the video is how I ended up here and its one of the few social media-esque sites I bother visiting. Taught me a pile of things about coding and CS that weren't in my mechanical engineering degree.
I thought this video was a lot better than the Veritasium video. The Veritasium video was awkward. I think they tried to follow the formula from the (excellent) blue led video that performed so well, but it just didn't work.
Disagree, I thought the Veritasium video was fantastic. You understand how the machine works in depth, the history of its development and challenges it encountered, and hear from people actively working on it. It’s a science lesson and history lesson. Like usual, they keep the video engaging and focused on the story, while still keeping a lot of depth with the science. It’s a great format
The whole “exploding tiny drops of metal” in the middle of this is just Loony Toons. This machine is literally insane and two of the companies I am long-long on would be completely fucked without it.
IIRC from the Veritasium video[0] there is actually some hydrogen gas flowing at quite a high speed though the laser chamber to carry away the tin debris so that it does not accumulate on the mirrors.
Seeing this news story made me briefly fear that they’d found a way to replace this glorious mechanism. Thankfully not. In fact, they’re going to shoot more droplets, more often!
Yes it was crazy when I first heard about it "wait what? they shoot it in mid-air?" and that was before I found out they did that like 30k times a second.
But now 100k times a second apparently. Humans are amazing.
You have a machine that’s basically a clean room inside and one of the parts is essentially electrosputtering tin but then throwing all the tin away and using the EM pulse from the sputter to do work.
Oh and can you build it so it can run hundreds or thousands of hours before being cleaned? Thanks byyyyyyyyeeeeee!
The thing I didn't understand after watching that video was why you need such an exotic solution to produce EUV light. We can make lights no problem in the visible spectrum, we can make xray machines easily enough that every doctors office can afford one, what is it specifically about those wavelengths that are so tricky.
The efficiency of X-ray tubes is proportional to voltage, and is about 1% at 100kV voltage. This is the ballpark for the garden variety Xray machines. But the wavelength of interest for lithography corresponds to the voltage of only about 100V, so the efficiency would be 10 parts per million.
The source in the ASML machine produces something like 300-500W of light. With an Xray tube this would then require an electron beam with 50 MW of power. When focused into a microscopic dot on the target this would not work for any duration of time. Even if it did, the cooling and getting rid of unwanted wavelengths would have been very difficult.
A light bulb does not work because it is not hot enough. I suppose some kind of RF driven plasma could be hot enough, but considering that the source needs to be microscopic in size for focusing reasons, it is not clear how one could focus the RF energy on it without also ruining the hardware.
So, they use a microscopic plasma discharge which is heated by the focused laser. It "only" requires a few hundred kilowatts of electricity to power and cool the source itself.
The issue isn't in generating short wavelength light, it's in focusing it accurately enough to print a pattern with trillions of nanoscale features with few defects. We can't really use lenses since every material we could use is opaque to high energy photons so we need to use mirrors, which still absorb a lot of the light energy hitting them. Now this only explains why we need all the crazy stuff that asml puts in it's EUV machines to use near x-ray light, but not why they don't use x-ray or higher energy photons. I believe the answer to this is just that the mirrors they can use for EUV are unacceptably bad for anything higher, but I'm not sure
Photoresist too. XRays are really good at passing through matter, which is a bit of a problem when the whole goal is for them to be absorbed by a 100 nanometer thick film. They tend to ionize stuff, which is actually a mechanism for resist development, but XRay energies are high enough that the reactions become less predictable. They can knock electrons into neighboring resist regions or even knock them out of the material altogether.
It really is the specific wavelength. Higher or lower is easier. But euv has tricky properties which make it feasible for Lithography (although just barely it you have a look at the optics) but hard to produce with high intensities.
Specifically, what makes x-rays easy to generate are these: https://en.wikipedia.org/wiki/Characteristic_X-ray In essence, smashing electrons into atoms allows you to ionize the inner shell of an atom and when an electron drops down from an outer shell, the excess energy is shed as high-energy photons. This constrains the energy range of X-ray tubes ("smash electron into metal") to wavelengths well below 13.5nm.
(These emission lines are also what is being used in x-ray spectroscopy to identify elements)
There are no normal x-ray mirrors. The only way to focus them is to use special grazing mirrors where the x-rays hit them almost parallel to the surface.
As I understand it, primarly because due to the high energy level of x-rays, light x-ray interacts very differently with materials[1]. Primarily they get absorbed, so very difficult to make mirrors or lenses, which are crucial for litography to redirect and focus the light on a specific miniscule point on the wafer.
The primary method is to rely grazing angle reflection, but that per definition only allows you a tiny deflection at a time, nothing like a parabolic mirror or whatnot.
All of these problems or equivalent still exist in EUV. Litho industry had to kind of rethink the source and scanner because it went from all lenses to all mirrors in EUV. This is also why low NA and high NA EUV scanners were different phases.
As I hear it, the decision had large economic component related to Masks and even OPC.
100%. EUV barely works. XRay litho takes all the issues with EUV and cranks them up to 11. It will take comparable effort to EUV, if not more, to get XRay litho up and running, and I'm not aware of anyone approaching this to anywhere near the level of investment that ASML (and others) have pumped into developing EUV tech. We may get there eventually as a species, but we're a ways off.
Stochastic effects become a bigger and bigger problem. At some point (EUV) a single photon has enough energy to ionize atoms, causing a cascade that causes effects to bloom outside of the illumination spot.
> The key advancements in Monday's disclosure involved doubling the number of tin drops to about 100,000 every second, and shaping them into plasma using two smaller laser bursts, as opposed to today's machines that use a single shaping burst.
This is covered in that video. Did they let him leak their Q1 plans?
That has been covered before in other videos[0] that this is their roadmap to higher power, so I'm also not sure what they have announced now that wasn't previously announced.
From the first video I thought they had already shipped this, but it sounds like they were describing what their new model was.
This seems like a product with a very very long sales pipeline, so I wonder if they work on pre-orders with existing customers but announce delivery milestones only as they come?
https://www.youtube.com/watch?v=B2482h_TNwg