Effects of metrology load port buffering in automated 300 mm factories

This report describes a simulation study characterizing the advantages and disadvantages of implementing multiple load ports on metrology equipment in a semiconductor factory. Three methods of automated material handling (AMH) for 300 mm. wafer carriers in four separate models were analyzed: through stocker, point-to-point, and conveyor (slow and fast velocity). Parameters measured include idle times of metrology equipment as number of load ports change and the effects on bottleneck equipment, work in process (WIP), queue lengths, transport times, delays waiting for transportation to begin, and the effect on stocker utilization by bay.