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0 pointsbpavuk2mo ago0 comments

I'd like to hear more about these challenges

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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.

https://science.gsfc.nasa.gov/662/instruments/mirrorlab/xopt...

magicalhippo2mo ago

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.

[1]: https://en.wikipedia.org/wiki/X-ray_optics

newswasboring2mo ago

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.

itishappy2mo ago

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.

newswasboring2mo ago

If you think it barely works now, you should've seen it when we first started. Availability of a machine was "fuck you"% and the whole system was held together by duct tape, bubblegum and hope. Compared to that the current system is entirely controllable.

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itishappy2mo ago

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.

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UltraSane2mo ago

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.

https://science.gsfc.nasa.gov/662/instruments/mirrorlab/xopt...

magicalhippo2mo ago

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.

[1]: https://en.wikipedia.org/wiki/X-ray_optics

newswasboring2mo ago

As I hear it, the decision had large economic component related to Masks and even OPC.

itishappy2mo ago

newswasboring2mo ago

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itishappy2mo ago

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