Hacker News new | ask | show | jobs
by thmsths 459 days ago
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.
1 comments
stanleykm 459 days ago
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.
link
bobmcnamara 459 days ago
I would like to double check some units.

2-3 wafers per minute would be 120-18 wafers per hour - did you mean wafers per hour for both?

link
adgjlsfhk1 459 days ago
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?
link
cycomanic 459 days ago
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).

link
monocasa 459 days ago
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.

link