Scheduling of Multi-Finger-Robotic Cluster Tools with Multi-Space Process Modules

Robotic cluster tools have been applied for wafer fabrication. To improve the productivity of such a tool, one method involves increasing the number of spaces within a process module and the fingers on a robot arm, leading to multi-finger-robotic cluster tools with multi-space process modules. This study addresses the scheduling issue of four-finger-robotic cluster tools with four-space process modules, a commonly seen configuration in modern semiconductor fabs. Residency time constraints make the scheduling issue of such a tool more challenging. This study conducts an analysis of the steady-state operations of such a tool under two presented robot task sequences. Then, based on the temporal properties of the tool, two linear programs are developed to find feasible schedules to minimize the system cycle time. Experiments show the performance of a tool under different robot task sequences by considering different parameters.