> It would probably take like 3 to 5 years to catch up with the benefit of hindsight and existing talent and tools?
Are you talking about TSMC - because that is a single, albiet primary, node in a supply chain, that's also what you have to replicate. AMSL is another vital node.
So many people with "it's just a factory, how hard can it be". The answer is "VERY", as a few endavours have found out already - and they will probably find out even at TSMC Arizona.
I shall illustrate with Adrian Thompson's 1996 FPGA experiment at the University of Sussex.
Thompson used a genetic algorithm to evolve a circuit on an FPGA. The task was simple: get it to distinguish between a 1kHz tone and a 10kHz tone using only 100 logic gates and no system clock.
After about 4,000 generations of evolution, the chip could reliably do it but the final program did not work reliably when it was loaded onto other FPGAs of the same type.
When Thompson looked inside at what evolved, he found something baffling:
The plucky chip was utilizing only thirty-seven of its one hundred logic gates, and most of them were arranged in a curious collection of feedback loops. Five individual logic cells were functionally disconnected from the rest - with no pathways that would allow them to influence the output - yet when he disabled any one of them the chip lost its ability to discriminate the tones.
Welcome to building semi-conductors.
https://www.damninteresting.com/on-the-origin-of-circuits/