Modeling and Scheduling of Cluster Tools Dealing with Wafer Revisiting: A Brief Review

For some fabrication processes, such as atomic layer deposition, wafers need to visit some process modules for a number of times, instead of once, thus leading to a revisiting process. It is complicated to schedule cluster tools with wafer revisit in semiconductor fabrication. This paper briefly discusses the modeling and scheduling issues for cluster tools dealing with a revisiting process. Then, we review and compare the methods for their modeling and scheduling. Finally, future research directions and conclusions with a revisiting process are finally given.