Glossary

Also in the app

Press ? in Fab Dispatch to read this in the help center, or / to ask the assistant.

Tool-down. An unplanned failure that stops a process tool. It has a response window: the engineer must start within it.

Bottleneck down. A tool-down on the fab's bottleneck (constraint) tool family, usually lithography. Priority 3. Every minute it's down costs wafer moves for the whole fab.

PM (preventive maintenance). Planned work with a wider window. Priority 1.

Priority. 3 = bottleneck down, 2 = other tool-down, 1 = PM.

Response window. When work may start: from when the job is reported to its latest start. The widths come from the fab profile's preset (for example 45 min for a bottleneck down and 120 for a tool-down in Fab 1's normal shift, 40 and 120 in Fab 2's, 25 and 60 in an excursion); PMs get 240.

Certification and level. An engineer is certified per tool family at level 1 (basic) to 3 (expert). A job needs a minimum level.

Home bay. Where an engineer starts the shift.

Aisle distance. Walking along the fab's grid of aisles (along, then across), not in a straight line.

Tool family. A group of tools of one kind, such as Etch or CMP, in its own area of the floor.

Excursion. In a fab, a process or yield deviation (an SPC excursion) handled by lot holds and an out-of-control action plan, not by maintenance dispatch. In this app, Excursion / surge is a preset that models a surge of unplanned tool-downs with tight response targets.

Wafer moves. Wafer-steps processed per period, a throughput activity metric. The fab's output is measured in wafers (or good die) out; a down bottleneck tool costs moves now and output later.

Fab profile. The data describing one fab: floor, tool families, faults, shift pattern and presets. See Fabs and profiles.