smif (standard mechanical interface)

SMIF (Standard Mechanical Interface) pods are sealed containers that hold wafers in a contamination-controlled environment during transport. **Purpose**: Protect wafers from particles during transport and storage. Isolate wafers from fab ambient. **Design**: Sealed plastic pod with door that only opens when docked to tool. Wafers in slots inside. **FOUPs**: Front Opening Unified Pods are the evolution of SMIF for 300mm wafers. 25-wafer capacity. **Standard**: SMIF is SEMI standard for 200mm and earlier. FOUP for 300mm wafers. **Isolation concept**: Wafer carrier interior stays clean even in less-clean fab areas. Mini-environment. **Docking**: Pod door couples with tool load port. Only opens in controlled environment. **N2 purge**: Advanced FOUPs can be purged with nitrogen to limit oxidation. **Cleanliness**: Particles inside pod minimized. Pod cleaning and maintenance required. **Automation**: Designed for automated transport via OHT (overhead hoist transport) or AGV. **Material**: Special plastics that minimize particle shedding and outgassing.