An Efficient Integrated Scheduling Method for Twin-Cluster Tools with Buffer Space Configuration

For improving the efficiency and reducing the processing load of a single tool, as novel equipment that have multiple processing routes, twin-cluster tools are widely used in wafer manufacturing. Periodic schedule has an important role in controlling wafers quality. It is meaningful to schedule a twin-cluster tool such that, processing routes in the tool work periodically. To achieve this goal, the workload of each module is carefully analyzed, leading to that the optimal cycle time of the system can be obtained. Then, a mathematical programming model is presented to make sure twin-cluster tools achieve the minimal cycle time. Further, a novel algorithm is established so as to obtain the robot waiting time. Furthermore, several sufficient conditions are proposed to guarantee that twin-cluster tools achieve the optimal cycle time. Finally, numerous experiments are conducted to verify the accuracy of the conclusion with different conditions.