When solving voltage sag immunity issues for a semiconductor processing facility, the
immunity of all interlocking subsystems must be considered. For example, if the process vacuum pump package shuts down as a result of a voltage sag event, the tool operations are likely to halt as
well. Furthermore, a shutdown of the Process Cooling Water (PCW) pumps or exhaust system can lead to immediate shutdown of tooling operations. For the semiconductor processing tool to continue
to operate during typical voltage sag events, the tool itself must be robust to power quality variations as well as the support systems.