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e-beam litho is anything but fast though: the machines are cheaper but they are much much slower in wafer throughput than the insanely expensive ASML EUV machin

e-beam litho is anything but fast though: the machines are cheaper but they are much much slower in wafer throughput than the insanely expensive ASML EUV machines. Now the website claims a fast fab, but leaves it open what that means: fast production of wafers? Or slow production of wafers that run fast?

naasking 4y ago
e-beam litho just seems strange to me since electron beam 3D printing is just as fast as using lasers, so clearly the scanning part isn't the bottleneck. What is the bottleneck in this case?
- chrisjc 4y ago
  > since electron beam 3D printing is just as fast as using lasers Interesting. What sort of resolution is that 3D printing though? > What is the bottleneck in this case? My guess would be using a single beam? Perhaps it's possible to scale this up to multiple beams working on a die or wafer at a time time? Which brings up another interesting question. Would this process require the same kind of wafer/substrate as traditional EUV machines? Perhaps using this approach opens up the possibility of using different materials that are easier, cheaper and faster to produce? Dont't traditional kinds of wafers have to be grown and sliced from exotic/rare materials? If so the additional time to "etch" with this new process might be offset by other factors such as what goes in to preparing the wafer?
  - naasking 4y ago
    > Interesting. What sort of resolution is that 3D printing though? Around 50 microns I believe. Not at lithography resolutions obviously, but that's limited by metal powder grain size. > My guess would be using a single beam? Electron beams can scan a whole print bed very quickly to heat up the whole top layer [1] which can't be done using lasers. This can be done easily with electrons since they are deflected using magnetic coils, like good old CRT monitors, but this can't be done using lasers because they have to move the mirrors mechanically. That's why it seemed weird that photolithography would be so much faster, but maybe it's as you say, lasers can be stacked for parallelism to make up for those downsides. Stacked electron beams might interfere with each other because you can't really isolate magnetic fields. [1] https://www.youtube.com/watch?v=jqjD-FWMexo https://www.youtube.com/watch?v=jqjD-FWMexo
    - amluto 4y ago
      Photolithography fabs don’t use scanning lasers — they shine light through a mask and expose a large area at once.
      - naasking 4y ago
        Crazy they have physical masks with features as small as 7nm. I assume those are movable somehow but that seems like incredibly delicate work.
        kosievdmerwe 4y ago
        You can use lenses and curved mirrors to make a larger mask focus the light onto a smaller area.
        naasking 4y ago
        That still seems pretty delicate. The lenses and mirrors would have to be aberration-free to an extreme degree so as to not introduce too many artifacts, and moving the mask further from the surface would increase risk of diffraction artifacts, no?
        haneefmubarak 4y ago
        It is, but that's how modern semiconductor lithography is done. Massive lenses and mirrors (both made of different materials that normal, since they need to have optical properties at wavelengths much smaller than human vision) are manufactured at great cost to ensure that it is free of aberrations. The extremely limited supply of these is actually one of the many factors that restricts the ability to move to newer processes and scale production capability of newer lithographies.
        naasking 4y ago
        For good telescope optics, we look for something like 1/4 - 1/6 wavelength tolerance, minimum. That's for optical wavelengths, but photolithography is in the UV range, so that's already stricter tolerance in absolute terms because of the shorter wavelength, but how does the tolerance in relative terms compare? Thanks for the info!
- thinkyfish 4y ago
  EUV can expose a whole chip image in a single shot. Raster scanning electrons takes about 4 hours to do the same image.
- ThePhysicist 4y ago
  You need to deposit a specific amount of energy into your resin to polymerize it, that takes time as you can't just crank up the amount of charge or the energy / electron in your e-beam as that will usually increase the energy variance and thereby the aberration. It's much easier to produce a coherent beam of light with sufficient energy than a coherent beam of electrons with comparable energy.
- jjk166 4y ago
  No the scanning is the bottleneck, scanning laser photolithography is equally slow. For mass production of chips, photolithography is done with a light source that illuminates a "large" area all at once.
cma 4y ago
If the machines could be super cheap you could make up for slow by having many run in parallel (~~not parallel beams working on same chip, since electrons deflect each other, but machines running in parallel~~). Edit: linked below, https://www.ims.co.at/en/products/ https://www.ims.co.at/en/products/ , says it uses 512x512 beams with a beam field of only 82um. Is that spacing between beams, or width of all the beams together?
- Zigurd 4y ago
  Back-of-the-envelope, a beam array of 256k beams could plausibly level that 1 minute vs 1 day ratio.
- nwiswell 4y ago
  The machines themselves couldn't be "super" cheap, that's impossible. You still have to deposit the e-beam resist while keeping the wafers extremely clean. This is non-trivial. The only route to economic viability is absolutely massive beam parallelism inside the tool. But at that scale, there's serious questions about accuracy/reliability. Just one out of hundreds of thousands (or millions) of beams fails for a microsecond and the chip is ruined. This is a problem that is effectively sidestepped for traditional litho -- the masks themselves are created by (slow) e-beam, but mask inspection tools ensure that the masks are perfect before they are actually used to process product wafers.
  - AaronFriel 4y ago
    > The machines themselves couldn't be "super" cheap, that's impossible. There are a few dimensions of cost that can be optimized though, right? My understanding is that ASML is making ~10s of these EUV machines per year because of the extreme complexity of many components.
    - nwiswell 4y ago
      Sure. Chief among those dimensions is the fact that it's not used as a serious production technology, so the manufacturing of these systems doesn't benefit from economy of scale. E-beam certainly does provide a bounding limit on how expensive EUV can get, but we're not in danger of hitting that limit anytime soon. I expect that EUV will become cheaper/more productive per dollar in the medium term, unless ASML starts acting uncomfortably monopolistically (and it's probably in their interest to drive EUV adoption to starve out Nikon and Canon, anyway)
zymhan 4y ago
I presume meaning "fast turnaround on producing a design", i.e. less time needed to setup tooling. Like the concept of Fast Fashion
- fsociety 4y ago
  My short introduction into the fab industry exactly echos this. Allowing US companies to turnaround prototypes quickly is a valuable business. Perhaps they aim to get a foothold with this and slowly ramp up to high volume manufacturing.

naasking 4y ago

e-beam litho just seems strange to me since electron beam 3D printing is just as fast as using lasers, so clearly the scanning part isn't the bottleneck. What is the bottleneck in this case?

chrisjc 4y ago
> since electron beam 3D printing is just as fast as using lasers Interesting. What sort of resolution is that 3D printing though? > What is the bottleneck in this case? My guess would be using a single beam? Perhaps it's possible to scale this up to multiple beams working on a die or wafer at a time time? Which brings up another interesting question. Would this process require the same kind of wafer/substrate as traditional EUV machines? Perhaps using this approach opens up the possibility of using different materials that are easier, cheaper and faster to produce? Dont't traditional kinds of wafers have to be grown and sliced from exotic/rare materials? If so the additional time to "etch" with this new process might be offset by other factors such as what goes in to preparing the wafer?
- naasking 4y ago
  > Interesting. What sort of resolution is that 3D printing though? Around 50 microns I believe. Not at lithography resolutions obviously, but that's limited by metal powder grain size. > My guess would be using a single beam? Electron beams can scan a whole print bed very quickly to heat up the whole top layer [1] which can't be done using lasers. This can be done easily with electrons since they are deflected using magnetic coils, like good old CRT monitors, but this can't be done using lasers because they have to move the mirrors mechanically. That's why it seemed weird that photolithography would be so much faster, but maybe it's as you say, lasers can be stacked for parallelism to make up for those downsides. Stacked electron beams might interfere with each other because you can't really isolate magnetic fields. [1] https://www.youtube.com/watch?v=jqjD-FWMexo https://www.youtube.com/watch?v=jqjD-FWMexo
  - amluto 4y ago
    Photolithography fabs don’t use scanning lasers — they shine light through a mask and expose a large area at once.
    - naasking 4y ago
      Crazy they have physical masks with features as small as 7nm. I assume those are movable somehow but that seems like incredibly delicate work.
      - kosievdmerwe 4y ago
        You can use lenses and curved mirrors to make a larger mask focus the light onto a smaller area.
        naasking 4y ago
        That still seems pretty delicate. The lenses and mirrors would have to be aberration-free to an extreme degree so as to not introduce too many artifacts, and moving the mask further from the surface would increase risk of diffraction artifacts, no?
        haneefmubarak 4y ago
        It is, but that's how modern semiconductor lithography is done. Massive lenses and mirrors (both made of different materials that normal, since they need to have optical properties at wavelengths much smaller than human vision) are manufactured at great cost to ensure that it is free of aberrations. The extremely limited supply of these is actually one of the many factors that restricts the ability to move to newer processes and scale production capability of newer lithographies.
        naasking 4y ago
        For good telescope optics, we look for something like 1/4 - 1/6 wavelength tolerance, minimum. That's for optical wavelengths, but photolithography is in the UV range, so that's already stricter tolerance in absolute terms because of the shorter wavelength, but how does the tolerance in relative terms compare? Thanks for the info!
thinkyfish 4y ago
EUV can expose a whole chip image in a single shot. Raster scanning electrons takes about 4 hours to do the same image.
ThePhysicist 4y ago
You need to deposit a specific amount of energy into your resin to polymerize it, that takes time as you can't just crank up the amount of charge or the energy / electron in your e-beam as that will usually increase the energy variance and thereby the aberration. It's much easier to produce a coherent beam of light with sufficient energy than a coherent beam of electrons with comparable energy.
jjk166 4y ago
No the scanning is the bottleneck, scanning laser photolithography is equally slow. For mass production of chips, photolithography is done with a light source that illuminates a "large" area all at once.

cma 4y ago

If the machines could be super cheap you could make up for slow by having many run in parallel (~~not parallel beams working on same chip, since electrons deflect each other, but machines running in parallel~~). Edit: linked below, https://www.ims.co.at/en/products/ https://www.ims.co.at/en/products/ , says it uses 512x512 beams with a beam field of only 82um. Is that spacing between beams, or width of all the beams together?

Zigurd 4y ago
Back-of-the-envelope, a beam array of 256k beams could plausibly level that 1 minute vs 1 day ratio.
nwiswell 4y ago
The machines themselves couldn't be "super" cheap, that's impossible. You still have to deposit the e-beam resist while keeping the wafers extremely clean. This is non-trivial. The only route to economic viability is absolutely massive beam parallelism inside the tool. But at that scale, there's serious questions about accuracy/reliability. Just one out of hundreds of thousands (or millions) of beams fails for a microsecond and the chip is ruined. This is a problem that is effectively sidestepped for traditional litho -- the masks themselves are created by (slow) e-beam, but mask inspection tools ensure that the masks are perfect before they are actually used to process product wafers.
- AaronFriel 4y ago
  > The machines themselves couldn't be "super" cheap, that's impossible. There are a few dimensions of cost that can be optimized though, right? My understanding is that ASML is making ~10s of these EUV machines per year because of the extreme complexity of many components.
  - nwiswell 4y ago
    Sure. Chief among those dimensions is the fact that it's not used as a serious production technology, so the manufacturing of these systems doesn't benefit from economy of scale. E-beam certainly does provide a bounding limit on how expensive EUV can get, but we're not in danger of hitting that limit anytime soon. I expect that EUV will become cheaper/more productive per dollar in the medium term, unless ASML starts acting uncomfortably monopolistically (and it's probably in their interest to drive EUV adoption to starve out Nikon and Canon, anyway)

zymhan 4y ago

I presume meaning "fast turnaround on producing a design", i.e. less time needed to setup tooling. Like the concept of Fast Fashion

fsociety 4y ago
My short introduction into the fab industry exactly echos this. Allowing US companies to turnaround prototypes quickly is a valuable business. Perhaps they aim to get a foothold with this and slowly ramp up to high volume manufacturing.