I have no idea what a fab is
Fabrication plant. They make chips.
Here a good vid that discusses the history of TSMC, the preeminent player in this space. Gets into strategic issues involving China, Taiwan, US.
Taiwan’s SECRET WEAPON against China - A History of TSMC
https://youtu.be/TNwnyA_N9ZM
Worth the 30m.
Here's one of them.
I believe it is the current vernacular for a manufactory facility.