[timelined]

IBM/Intel/Samsung buy tools from various companies. By "tools", I really mean huge pieces of instrumentation that cost many (tens to hundreds) millions of dollars from other companies that are used for the various processing steps (deposition/growth of materials on wafers, patterning resists, etching, etc). The development of each of these tools is immensely difficult and challenging and making them talk to each other and designing manufacturing pipelines is another immense challenge. IBM/Intel/Samsung's job is to design chips (a immense challenge on its own), come up with a process to manufacture them, and then take each of these very complex tools, integrate them into a manufacturing pipeline (with QC), and manufacture the devices that they want.

[graycat]

How much is like turn key and how much is lots of one off, proprietary engineering and system integration?

I was guessing that maybe for the fabs themselves, mostly there was some one company that delivered fabs. Or, why reinvent the wheel several times?

Sure, for the chip design, say, by Qualcomm, Samsung, Intel, IBM, that's a lot of design software, know how, etc. And, sure, QC has to be one heck of an Excedrin headache but with likely some long standing basic ideas for testability.