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.

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2 hours ago | parent | next [-]

[deleted]

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zozbot234 2 hours ago | parent | prev | next [-]

There is such a thing as X-ray lithography, but it comes with significant challenges that make it not really worth it compared to EUV.

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bpavuk 2 hours ago | parent [-]

I'd like to hear more about these challenges

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magicalhippo an hour ago | parent [-]

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

	▲	newswasboring 37 minutes ago \| parent [-]
		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.

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on_the_train 3 hours ago | parent | prev [-]

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.

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formerly_proven 2 hours ago | parent | next [-]

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)

	▲	s0rce 2 hours ago \| parent [-]
		You can also generate broad spectrum bremsstrahlung radiation easily, this is widely used for medical X-rays.

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YetAnotherNick 3 hours ago | parent | prev [-]

Any source to this? I am hearing this for the first time.

	▲	s0rce 2 hours ago \| parent [-]
		ITs easy to make X-rays, you just hit a metal target with electrons: https://en.wikipedia.org/wiki/X-ray_tube