Abstract
Equipment capability and dedication are specific constraints of wafer fabrication. Photolithography is a critical process in wafer fabrication. Meeting tolerances on the critical dimensions (e.g., line width) and alignment with the previous layers are critical to the manufacturing of ultra large scale integrated circuit (ULSI). Therefore, it is a common practice to dedicate lots to the same photolithography equipment, i.e., to process all the layers of a given lot by the same equipment. As a result, it is important to balance the loading among different machines with the same capability to improve the productivity. This project develops a capacity planning system (CPS) that integrates order assignment and load allocation considering equipment capability and dedication for semiconductor foundry companies that has multiple fabs with equipment of different capacity and capability. Simulation can be used to evaluate the performance of CPS. Order assignment can efficiently balance the equipment workload among the various fabs, on various days at various levels of demands. Load allocation can effectively balance the loading among different machines with the same capability on the planning horizon by taking into account the order's process requirements as well as the machine's capacity, capability, and dedication constraints. CPS can help semiconductor foundry companies to obtain better resource utilization, more balanced equipment loading among different fabs and also among different machines with the same capability, shorter manufacturing lead time, better on-time delivery, and lower work-in-process.