What do mean by "technician"?, I had thought of the term as the same as operator. Do you mean what I think of as "craftsman" or "maintenance" (depending on whether they skillfully re-align the pump or beat on it with a big pipe wrench)? Engineer? Something in between?
In the land of PN junctions, the terminology is as follows.
Operators move wafers around, the fab, load them on tools, follow work instructions, but do not make any judgements or decisions. This is hourly pay and often contract work.
Process Technicians follow higher-level guidelines to inspect, test, and disposition nonconforming material. They also run offline or otherwise special experiments for Engineers, where SOP does not exist. This is hourly work.
Process Engineers write the work instructions, disposition guidelines and experiments, and disposition material in situations where no guidelines exist. They also own yield and scrap. For example, if a Process Tech makes a bad call and scraps material, it is still the Process Engineer's fault (he should have written better procedures or intervened himself; it is never possible to throw techs under the bus). This is a salaried position.
Equipment maintenance is separate. It typically has a tech+engineer structure, with techs doing repairs and preventive maintenance, and engineers writing the PM procedures and owning equipment uptime, performance and cost. There is crossover between Equipment Engineers and Process Engineers because the process results are tied to the equipment. In some facilities they are consolidated into one Fab Engineer.
My beef with my current role is that I am both Process Engineer and Equipment Engineer at a start-up company, for a very large department. I also have no dedicated technicians, so I get pulled into technician level work by production imperatives, resulting in long irregular hours and substandard engineering results. The work is, as startup HR departments are wont to describe them "exciting and dynamic", but the pay is merely average and the general trajectory of things is a train wreck and quite "no-win".