Just to buttress and embroider around your point that a fab is not a small business:

If there was a realistic way even to go from bare wafers to non-trivial custom chips in a small-batch fashion, you can bet there would be a cottage industry around it. I would love to live in a world where I could manufacture custom silicon as easily as I can manufacture a custom PCB or custom mechanical part.

But as it stands, quick-turn, rapid-proto "micro" fabs are obscenely expensive, to the extent that if you aren't absolutely certain you need the performance gains from custom silicon, justified by years of R&D that confirms the inadequacy of a multi-chip solution, then the idea is killed before any layout engineer is contacted.

Microfabs are either operated by research institutes, or they're booked solid for years, and basically printing money.

> Fabs are optimized for utilization - throughput, not latency

I remember hearing some company trying for the speed

> A fab is not a small business!

An SBIR is just a cost effective way for the government to put a number of PhDs/engineers to work on a problem.

The time from tapeout to first samples is 3-4 months even for the biggest customers of TSMC.

Shorter for a metal only change.