Japanese researchers testing particle accelerator for chipmaking — researchers claim EUV-like lithography capabilities

TSMC
(Image credit: TSMC)

Intel, Samsung Foundry, and TSMC use ASML's EUV lithography machines, which are capable of 'printing' semiconductors at a 13nm resolution, to build chips on their latest fabrication nodes. But using a laser produced plasma (LPP) EUV light source (which is a CO2 laser applied to small tin droplets) is not the only way to generate 13.5 nm EUV radiation to 'print' chips. Researchers in Japan are exploring the usage of free-electron lasers (FELs) from particle accelerators to make chips with leading-edge feature sizes, reports Spectrum.IEEE.org

The High Energy Accelerator Research Organization (KEK), in Tsukuba, Japan, is exploring usage of free electron lasers (FELs) generated by an energy recovery linear (ERL) accelerator for chipmaking. They say that an energy recovery linear accelerator could produce tens of kilowatts of EUV power cost-effectively to power multiple lithography machines simultaneously. By contrast, ASML has produced a 500W EUV light source for its Twinscan NXE:5800E and is looking at potentially improving power of its EUV light sources to 1000W — eventually.

ERL works completely differently from an EUV litho tool. First, an electron gun injects electrons into a cryogenically cooled tube, where superconducting RF cavities speed them up. The electrons pass through an undulator, emitting light that is amplified through a process called self-amplified spontaneous emission (SASE). After emitting light, the spent electrons loop back into the RF accelerator in the opposite phase, transferring their remaining energy to newly injected electrons before being disposed of in a beam dump. This energy recovery allows the ERL to use the same amount of electricity to accelerate more electrons, making it a highly efficient and cost-effective method for generating extreme-power EUV light. 

"The FEL beam's extreme power, its narrow spectral width, and other features make it suitable as an application for future lithography," Norio Nakamura, researcher in advanced light sources at KEK, told Spectrum.IEEE.org in an interview.

In 2021, prior to the onset of severe global inflation, the KEK team estimated the construction cost for a new ERL system at $260 million, which is $50 million - $60 million higher than the price of a Twinscan NXE:3800E — though the latter is a fully-integrated tool, whereas the former is essentially only a light source. This system would deliver 10 kW of EUV power, supply multiple lithography machines (KEK does not specify how many), and its annual operating costs were projected to be around $25.675 million. 

"The estimated costs per exposure tool in our setup remain relatively low compared to the estimated costs for today’s laser-produced plasma source," Nakamura told Spectrum.IEEE.org. 

There are a few slight problems with FELs and ERLs. First, like any particle accelerator, an energy recovery linear accelerator is huge. Second, one needs an extremely complex set of mirrors to guide that 10 kW of EUV radiation to multiple litho tools without significant loss of power, and that set has not been invented yet (and its costs are unclear). 

Finally, assuming that there is a complex set of mirrors that can guide 10 kW of EUV radiation to 10 litho tools, there are no resists and pellicles that are compatible with such a powerful light source. That is not going to be a problem, though, because for now an experimental ERL can produce bursts of 20micrometer infrared light — which is a far cry from 13.5nm EUV light.

Nakamura acknowledged that numerous technical challenges must be resolved before an ERL-based litho tool can achieve the high levels of performance and operational stability required for commercial chipmaking.

Anton Shilov
Contributing Writer

Anton Shilov is a contributing writer at Tom’s Hardware. Over the past couple of decades, he has covered everything from CPUs and GPUs to supercomputers and from modern process technologies and latest fab tools to high-tech industry trends.

  • The electrons pass through an undulator, emitting light that is amplified through a process called self-amplified spontaneous emission (SASE).

    No, to put this more clearly, basically the undulators force the electrons which are of course speeding to follow a "sinusoidal" route, and thus this motion causes the electrons to emit light. SASE happens after this.

    BTW, spatio-temporal splitting of FEL pulses can help mitigate the coherence and speckle-related obstacle and challenges we might still face. Though, I wouldn't worry much about this yet.

    Because we can't ignore FEL's characteristics akin to shorter pulse duration, narrower bandwidth, and of course higher repetition rate.

    But last year, the researchers already submitted a journal related to testing done on High-power EUV free-electron laser for future lithography. And actually the good part is that despite the high peak power of FELs, the design of the scanner still ensures that the risk of damage to optics is minimal.

    Paper which was published on 19 April 2023:

    https://iopscience.iop.org/article/10.35848/1347-4065/acc18c/pdf
    Reply
  • TechyIT223
    So it's basically old research tech ?
    Reply
  • ivan_vy
    Metal Messiah. said:
    No, to put this more clearly, basically the undulators force the electrons which are of course speeding to follow a "sinusoidal" route, and thus this motion causes the electrons to emit light. SASE happens after this.

    BTW, spatio-temporal splitting of FEL pulses can help mitigate the coherence and speckle-related obstacle and challenges we might still face. Though, I wouldn't worry much about this yet.

    Because we can't ignore FEL's characteristics akin to shorter pulse duration, narrower bandwidth, and of course higher repetition rate.

    But last year, the researchers already submitted a journal related to testing done on High-power EUV free-electron laser for future lithography. And actually the good part is that despite the high peak power of FELs, the design of the scanner still ensures that the risk of damage to optics is minimal.

    Paper which was published on 19 April 2023:

    https://iopscience.iop.org/article/10.35848/1347-4065/acc18c/pdf
    dude, you are awesome and always a delight to read your comments.
    Reply
  • TJ Hooker
    Metal Messiah. said:
    No, to put this more clearly, basically the undulators force the electrons which are of course speeding to follow a "sinusoidal" route, and thus this motion causes the electrons to emit light. SASE happens after this.
    I don't really see anything incorrect in what you quoted from the article. The self-amplification does occur within the undulator, along with the sinusoidal movement/light emission.
    Reply
  • As per the original source (spectrum.ieee),

    Other EUV Possibilities : It’s too early in the development of EUV free-electron lasers for rapidly expanding chipmakers to pay it much attention.

    KEK team is not alone in chasing the technology. A venture-backed startup xLight, in Palo Alto, Calif. is also among those chasing it.
    Reply
  • TechyIT223
    ivan_vy said:
    dude, you are awesome and always a delight to read your comments.
    :⁠-⁠)
    Reply