A dispatching method for the lots of different priorities in 450-mm semiconductor manufacturing

Abstract

Semiconductor industry grows rapidly in recent years. It has an impact on the economies all over the world. For the mass production requirement, the wafer size starts to be increased from 300 to 450 mm. The technician cannot handle a large number of wafers since the size and weight of the wafers are increased. The automated material handling system has become the basic requirements of the wafer factory, and it is important to provide on-time delivery service and shorten cycle time to meet customer demand for different priority products. Hence, this study proposed an effective conveyor dispatching rule, which can reduce the handling delay of hot lots and detect the dispatching of lots with different priorities. The simulation experiments were conducted by building a 450-mm manufacturing environment and compared the nearest job first with conveyor dispatching rule. The results are sound. The conveyor dispatching rule can reduce 97.57% of the total average delivery variable time of hot lots and 0.28% of normal lots. This study proves that conveyor dispatching rule can efficiently improve productivity and reduce the cycle time of hot lots in every load configuration.