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Comment by jmward01 | Hacker News Reader

I wonder if this has implications for custom home chips/prototyping. I'm sure a big issue is vibrations but something like this could remove the need for masks at least. (again, not my area so I am clobbering terminology I am sure). It may open up home fab capabilities.

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In general, hobby photo-lithography projects already use DMD/DLP projectors, and some inexpensive optics.

Huygens Optics:

https://www.youtube.com/watch?v=_w0Z2Y5vaAQ

Sam Zeloof:

https://www.youtube.com/watch?v=Nxz_ENnmgtI

In general, getting vanity silicon made is usually much less expensive than trying to bootstrap a fab line. =3

I think half the fun for people that do things like this is figuring out how to out innovate a multi-billion dollar company so that they can make something 1/4th as good but at 1/10000th the price. I bet there are some -really- innovative people out there that would figure alternatives to a lot of the expensive parts of the process and figure out how to be able to produce 2000's level chips at home. I'm not one of them though :)

The problem is that they aren't (yet) 1/4th as good for 1/10000th of the price. Patterning is just one part of the process - and not nearly the most difficult one.

I think abusing a write-off electron microscope to side step the need for masks is also an interesting idea, however, I believe acquiring wafers of sufficient quality and depositing layers to be etched could be the bigger challenge here.

And the clean environment as a whole. That's a massive investment and there are a million ways to mess that up.

> however, I believe acquiring wafers of sufficient quality and depositing layers to be etched could be the bigger challenge here

Definitely hard for a home fab but how about a community fab? Not necessarily a geographic community.

for making research grade devices you barely need a cleanroom

There's this guy doing clean room in a shed on YouTube: https://www.youtube.com/@Dr.Semiconductor

wafers are the easy bit.

Hold on, if I had an electron microscope, can I just put in a decapped cheap large format photodiode under it, jack the beam current way up, and start etching trenches on it?

I don't think so: it's a microscope, not a synchrotron. :D

I meant "drawing" on a photoresist layer with a SEM and then wet-etching it. Also all silicon in a photodiode is doped, so the etched parts would be of little use, I believe.

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