The cost of ownership of semiconductor manufacturing equipment is typically addressed in terms of raw utility
consumption. Focusing on energy, the average consumption of a typical semiconductor fabrication plant has doubled
over a recent 10 year period, with approximately 30% of this energy currently attributed to vacuum equipment.
Compared to conventional optical lithography, extreme ultraviolet lithography (EUVL) requires the adoption of a
vacuum subsystem to enable the technology, bringing an additional vacuum requirement to semiconductor fabs. With
this trend it is increasingly important to focus on more efficient ways of operating semiconductor manufacturing tools
and their supporting equipment. Clever operation through employment of 'GREEN' modes can provide significant utility
savings. However, in semiconductor lithography, tool uptime is a critical parameter to be considered in any cost of
ownership model, and the facility vacuum equipment plays an intimate role here, so including redundancy in pumping
equipment can be a key enabler to maintaining tool uptime. Consequently optimizing the design of the vacuum
subsystem will help to reduce the overall footprint, utility consumption and energy costs associated with this process.