How did SiFive get anywhere near 5nm TSMC?
But there are other intermediary companies that help startups group multiple chips from multiple companies together into a single mask. This is called a "shuttle" and allows the companies to split the costs of the masks (I've heard up to $30 million for 5nm)
SiFive is probably building about 2,000 of these chips for development boards. They aren't trying to order a hundred million like Nvidia.
Pretty classic "commoditize your complement".
When I worked at startups and smaller companies we have interacted with:
Global Unichip Corporation (I believe TSMC owns part of the company)
https://www.guc-asic.com/en-global
Open Silicon (they literally merged with SiFive to become OpenFive and made this chip in the article)
https://en.wikipedia.org/wiki/Open-Silicon
Uniquify
Socionext
There are others but these are the 4 that I have dealt with.
Plus it’s probably fun for some of the people there.
Other than that, foundries are known to sponsor IP development on their processes.
Would this mean the actual chip delivery may still be delayed?
For a small volume ‘shuttle’ run hopefully there won’t be delays, but this is not the same as having working chips!
The foundry will do initial checks it is manufacturable at ‘tapeout’ when you submit your design, but you don’t know for sure if your chip works with intended functionality until you get it back! You are relying on lots and lots of simulations up front before your ‘tape-out’.
Sometimes issues are found and a chip requires a re-spin - basically another go with the bugs fixed. You want to do this as few times as possible (ideally right first time) due to cost and time of these iterations.