Patent Document ID: 9227318
Application ID: 14639137
Patent Flag: 1

Claim One:
1. A computer implemented method for scheduling single-arm multi-cluster tools with optimal buffer space configuration, comprising: obtaining, by a processor, a wafer processing time, a robot wafer loading and unloading time, and a robot moving time; calculating, by a processor, a shortest time for completing a wafer based on the wafer processing time, the robot wafer loading and unloading time, and the robot moving time; calculating, by a processor, a robot cycle time based on the robot wafer loading and unloading time, and the robot moving time; determining, by a processor, a fundamental period based on selecting a maximum value among the shortest time for completing the wafer and the robot cycling time; determining, by a processor, a type of cluster tool by: if the fundamental period is a value of the shortest time for completing the wafer, the type of cluster tool is process-bound; otherwise the type of cluster tool is a transport-bound; determining, by a processor, the multi-cluster tools to be process-bound, or transport-bound based on the type of cluster tool having a maximum value of the fundamental period; determining, by a processor, a lower bound of cycle time based on the maximum value of the fundamental period; determining, by a processor, an algorithm for scheduling and buffer space configuration based on a petri net model; and calculating, by a processor, a robot waiting time based on the algorithm; calculating, by a processor, a wafer sojourn time based on the algorithm and the lower bound of cycle time; determining, by a processor, a buffer space for buffer module based on the wafer sojourn time and the robot waiting time; and obtaining, by a processor, a schedule based on the buffer space for buffer module and the lower bound of cycle time.