Yes, it's mostly the continual equipment maintenance and the occasional process engineer that goes actually looking at the equipment (mostly in drop bays) as wafers go by in boxes. Most of those are associates degree positions, because you need to understand enough (cleanliness, electronics, a little chemistry/optics, and some chemistry) to debug and replace components without breaking more stuff. Most of the equipment is manufactured, updated, and maintained/fixed by european, american, and japanese FAEs anyway.
That said, I do still hear that when there's an actual yield problem (or a delay in achieving yield), then there's a lot of overtime for the process engineers getting it up and running. Usually some engineer has to be on call all night in each area (photo, diff/dep, etch, implant), but in an office nearby.
Oh, and also there is all the process model extraction/control that has to be done for each fab/process. That's a whole group of serious engineers to create the PDKs.
That said, I do still hear that when there's an actual yield problem (or a delay in achieving yield), then there's a lot of overtime for the process engineers getting it up and running. Usually some engineer has to be on call all night in each area (photo, diff/dep, etch, implant), but in an office nearby.
Oh, and also there is all the process model extraction/control that has to be done for each fab/process. That's a whole group of serious engineers to create the PDKs.