I was hoping to see table top particle accelerators like those at UCLA were progressing into something usable for lithography. Which makes me wonder, why not use electrons instead of light?
From my non expert understanding, we already do kinda. The masks used for photolithography are made using an electron beam, allowing for a much greater resolution than what the underlying photolithography allows. But this is far too slow for large scale production.
Scanning an electron beam, repeatedly over an entire waffer would take forever. So instead we do it once, to make the mask, and that mask is then used over and over to expose the waffer.
This is a bit little injection molding: the mold is very expensive and made with a far better manufacturing process than the plastic pieces that it will eventually produce, but this is the price to pay for high volumes and low costs.
Adding to this, from what I’ve read electron beam is too slow for the required throughput. The ASML EUV machine can etch something like 170 wafers per hour. Using an electron beam would be far too slow for 2-3 wafers per minute.
It would be interesting to see if this tech was viable for dev boards. i.e. when you want to design a new 2nm chip, what if you were using electron beam chips to test out designs?
E-beam lithography is used for research purposes all the time, so yes it's already used for "dev-boards".
That said, apart from the economics (it is very slow), you are also constrained with respect to the size of what you can write, the writing fields is typically quite small, if you want to make a chip larger than that you need to stitch fields together and you have to deal with stitching errors (which becomes more and more difficult the smaller your structures are).
That would almost certainly be more expensive. When people talk about modern masks being $15M or so for each mask set, a huge fraction of the cost is this process for the masks.
It also doesn't tell you as much about how your design actually runs on the process in question.
That means each litho tool prints 6.75 x 10^13 “transistors” per hour. In more useful units, that’s 18.75B transistors per second.
Drawing them one line at a time is technically feasible but…I’ll bet you are talking single digit DIE per hour if that.
And that is for one layer of lithography. I’ve seen estimates from 5-20 layers of lithography using EUV tools at the 3-7nm nodes. So the time scale is even more warped.
It might be as simple as the fact that anything the electrons hit will pick up a huge electric charge. Now you've got ESD problems from hell, not to mention unwanted X-ray generation.
you can use an anti-charging layer for e-beam litho, that's not such a big deal. E-beam litho is just very slow. There are lithography techniques that use synchrotron sources like LIGA.
Scanning an electron beam, repeatedly over an entire waffer would take forever. So instead we do it once, to make the mask, and that mask is then used over and over to expose the waffer.
This is a bit little injection molding: the mold is very expensive and made with a far better manufacturing process than the plastic pieces that it will eventually produce, but this is the price to pay for high volumes and low costs.