I'm surprised lithography hasn't been replaced with something more nanoscale in origin like some kind of atomic deposition process where individual atoms are precisely bombarded onto the substrate to build up the features atom by atom.
It would take longer to manufacture each chip, but if the machines to do the deposition were relatively cheap and simple to construct, they're not that far off of electron beams, the result could be a massively parallel manufacturing process.
"Longer" if you're talking atom by atom is an understatement, you're going to almost never finish. Electron beams might be something relevant, but they're already being investigated.
E-beam lithography is a thing, and as with all next-gen litho techniques, it too has its fair share of problems. For example, shot noise is a major problem which means that every time you halve your node, you're going to halve your throughput. This is devastating for semiconductor manufacturing, TSMC is already working double shifts trying to match demand.
Also, the important thing to realize about semiconductors is that demonstrating something in the lab is a relatively easy ordeal, but making it mass manufacturable in a timely fashion with good yields is a herculean task. You can actually use X-ray litho for something more "nanoscale in origin" but it's really, REALLY difficult to make it in production.
Wouldn't that result in a threshold shift? (X-rays are well beyond Si02 bandgap, so you'd get electron-hole pairs in the oxide. The electrons are fairly mobile, but the holes get trapped iirc.)
Current production seems very counterintuitive from a manufacturing/industrial engineering perspective. There are around 9 main processes and only about 3 add material. Depending on the chip design, it's probably going to 500-2000 manufacturing steps. That being said, each silicon wafer can hold up to hundreds of chips, making for a big batch. Going up to 18" wafers would make it even more appealing to stick with current methods of production.
With how expensive all fab machines are, I don't see it becoming economical anytime soon for a complete overhaul of tooling.
"longer" is a bit of an understatement when lithography can sweep across a wafer at centimeters per second with nanometers of precision. Good luck ever finishing a single chip atom by atom.
I'm presuming with the right control you can fire out millions of atoms per second, possibly more if you have multiple "guns". I'm not talking about dropping each into place with some kind of claw.
It would take longer to manufacture each chip, but if the machines to do the deposition were relatively cheap and simple to construct, they're not that far off of electron beams, the result could be a massively parallel manufacturing process.