Glossary comparison
Lot vs Wafer: what is the difference?
The difference
A wafer is one disc; a lot is a group of wafers that move and are recorded together.
A lot is a group of wafers, commonly up to 25 in one carrier, that move through the fab together and share a history.
The two terms
Lot
The unit of material movement in a fab: a group of wafers, conventionally up to 25, that travel together through the process flow and share a lot number, run card and dispatch priority.
Wafer
A thin, polished disc of single-crystal silicon on which hundreds or thousands of identical circuits are built at the same time. It is the unit of work in a fab, moving through the line in cassettes or FOUPs before being diced into individual dies.
Side by side
| Field | Lot | Wafer |
|---|---|---|
| Stands for | Not an abbreviation | Not an abbreviation |
| Type | Term | Material |
| Domain | Fab Ops, Yield & Metrology | General Industry |
| Group | Fab operations | Silicon and form factors |