One of the funniest stories I heard was about the first copy of the Intel 14nm design rules Altera got from Intel. They were heavily redacted, which is something I had never seen in the foundry business.
https://semiwiki.com/semiconductor-manufacturers/intel/7912-...
Additionally, a contract fab tries to be flexible, easier to design for. They make their libraries & design rules work well with commercial design software. A private fab on the other hand can boost yield & performance by pushing increasingly complex design rules on the design team, and the design team can use customized or internally developed software to make it all work.
So in short, they had the best fab tech in the business but they weren't used to servicing anyone other than themselves.
(thanks for answer though)
Yes, it make perfect sense to optimise for you own yield and performance until TSMC overtake you and you no longer has the volume advantage. In manufacturing volume is everything.
It is also worth pointing out Altera is actually a Subsidiary of Intel. If that is what they were going through you can imagine about the others.
I've seen a tv-documentary about 15 years ago about their fabs. Therein some reporter asked why there was a bend in some bundle of pipes for no apparent reason. They answered that was there because in another factory there was a column there which they had to route around, which didn't exist at this factory. They explained further to not wanting to risk process variation, by building that bundle of pipes straight again. Since then i have been unimpressed by all that high-tech, being so complex, having to cargo-cult around, instead of being able to understand it from first principles and build according to the situation. Not blindly copying something which worked at another place but doesn't apply anymore, because the place and its conditions changed.
But see where it got them?
If it were your $$$billions being spent on a fab, what would you do?
/me lifts hat and bows.
Courtesy of Lilly, Mieze, and Mimi.
I'm actually surprised they didn't go and put a column there, too, just in case.
https://www.extremetech.com/computing/127987-deliberate-exce...
> Intel began working on CE! after it had trouble at the 0.5um (500nm) node and refined the process through each successive generation. The green line shows the initial product ramp at its first fab — after an early spike, yields cratered and only recovered over a period of months. Once Intel had Fab 1 working well on 0.5um, it started ramping Fab 2 only to run into new problems. As Copy Exactly! was developed and deployed, the company’s yields synchronized across the various fabs.
Because they don't know enough to predict the process effects of variations in humidity, barometric pressure — or pipe length! — they eliminate those variations instead. Presumably they would learn more if they didn't do that, but they would also take longer to ramp up production. Since they started doing CE! in the 1980s, it's probably not a primary cause of their late-2010s decline.