
Ask HN: How do you actually layer a chip? - snr
All the fab videos I could find on the internet talk about taking a single sheet of silicon, performing lithography and connecting components with copper wires. I don&#x27;t see how they build 10-30 layered chips. Is it that they layout all the layers on a single sheet and form virtual layers by copper wire interconnects?
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mchannon
As I understand it, they deposit a layer of oxide on the first layer, pattern
it, and preferentially etch in order to allow selective interconnection to the
existing layer, then deposit fresh layers of silicon on top to do it all over
again.

Chemical vapor deposition or sputtering is how they do deposition. Put wafer
in vacuum chamber, suck out all gas, then make the desired compound form by
zapping targets or cooking exotic gases like silane.

Sometimes, as with top-end solar cells, they'll even change the material from
layer to layer.

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snr
I thought CVD is used for laying out interconnects, no? It's used for laying
out silicon?

