Expeditious Hot Lots Handling in 300mm Semiconductor Foundry

Semiconductor manufacturing demands short cycle time of hot lots management for the purposes of process experiment, process characterization and design validation. To provide an almost no-wait transport for hot lots is become a serious issue under the 300 mm automatic material handling system environment. The purpose of this paper is to provide an effective OHT dispatching method for hot lots against the normal lots under 300 mm frequently blocking transportation situation. The objective is to minimize the transport delay of hot lots with least impact to the transport of normal lots. Simulation experiments based on realistic data from a Taiwan 300 mm wafer foundry fabrication are conducted. Numerical results demonstrate that our method can effective expedite the movement for both hot lots and normal lots when OHT´s amount is sufficient.