[HN Gopher] Want even tinier chips? Use a particle accelerator
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       Want even tinier chips? Use a particle accelerator
        
       Author : jdaw0
       Score  : 35 points
       Date   : 2025-03-17 18:35 UTC (3 days ago)
        
 (HTM) web link (www.economist.com)
 (TXT) w3m dump (www.economist.com)
        
       | jdaw0 wrote:
       | https://archive.ph/O9f3E
        
       | n0n0n4t0r wrote:
       | So they basically want to use synchrotron?
        
         | PaulHoule wrote:
         | 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 wrote:
           | 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).
           | 
           | https://www.nature.com/articles/s41598-022-07323-z
        
           | itishappy wrote:
           | 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...
           | 
           | https://www.euvlitho.com/2017/P18.pdf
        
         | phkahler wrote:
         | 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.
        
       | sroussey wrote:
       | 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 wrote:
         | 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 wrote:
           | 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.
        
             | adgjlsfhk1 wrote:
             | 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?
        
               | monocasa wrote:
               | That would almost certainly be more expensive. When
               | people talk about modern masks being $15M or so for each
               | mask set, a huge fraction of the cost is this process for
               | the masks.
               | 
               | It also doesn't tell you as much about how your design
               | actually runs on the process in question.
        
               | cycomanic wrote:
               | E-beam lithography is used for research purposes all the
               | time, so yes it's already used for "dev-boards".
               | 
               | That said, apart from the economics (it is very slow),
               | you are also constrained with respect to the size of what
               | you can write, the writing fields is typically quite
               | small, if you want to make a chip larger than that you
               | need to stitch fields together and you have to deal with
               | stitching errors (which becomes more and more difficult
               | the smaller your structures are).
        
         | CamperBob2 wrote:
         | 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 wrote:
           | 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.
        
         | xeonmc wrote:
         | Ebeam is a pencil, photolithography is a printing press.
        
       | spudnik wrote:
       | RTFA. It's not about using electrons instead of UV
        
       | kev009 wrote:
       | Is the idea that this will scale? You can already build down to
       | the atomic level with scanning tunneling microscopy (thanks IBM).
        
         | itishappy wrote:
         | 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.
        
       | JimBlackwood wrote:
       | 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 wrote:
         | Lead is cheap, right?
         | 
         | Very cool you visited ASML. Anything exciting/interesting you'd
         | be willing to tell the class?
        
       | elchananHaas wrote:
       | 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?
        
       | ur-whale wrote:
       | https://archive.is/HKDho
        
       | hengheng wrote:
       | 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.
        
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