Real-Time Scheduling and Control of Cluster Tools in Semiconductor Manufacturing

Cluster tools provide a flexible, reconfigurable, and efficient environment for semiconductor manufacturing. They become difficult to operate because of residency time constraints and process time variation. This talk addresses their real-time scheduling and control issues. A generic Petri net model is developed to model them. It describes the robot activity sequence with robot waits included. Hence, to operate a cluster tool is to determine robot wait times. A two-level operational architecture is proposed and discussed. It includes an off-line periodic scheduler and real-time controller. This proposed approach allows a cluster tool to adapt to activity time variation while operate at its highest throughput at the steady-state. MengChu Zhou is a Professor of Electrical and Computer Engineering and the Director of Discrete-Event Systems Laboratory at New Jersey Institute of Technology. His research interests are in Petri nets, semiconductor manufacturing, sensor networks, system security, and life-cycle engineering product design. He has over 300 publications including 7 books, 130+ journal papers, and 17 book-chapters. He is Editor of IEEE Transactions on Automation Science and Engineering, and Managing Editor of IEEE Transactions on Systems, Man and Cybernetics: Part C, Associate Editor of IEEE Transactions on Systems, Man and Cybernetics: Part A and IEEE Transactions on Industrial Informatics, and Editor-in-Chief of International Journal of Intelligent Control and Systems. He is Fellow of IEEE.