Abstract
Improving throughput and quality control in the wafer process steps are important elements in semiconductor manufacturing. Wafer transfer schedule optimization has a significant impact on these factors. Wafer process steps are becoming more complex, so the importance of flexible and efficient wafer transfer schedule optimization methods is increasing. Therefore, we have developed a cluster tool simulator that has fewer constraints than real equipment and can be used to verify wafer transfer schedule optimization algorithms. This paper reports the results of the verification of the processing sequence optimization method by the Monte Carlo method with the simulator. The Monte Carlo method is applicable to complex wafer process steps because it does not require evaluation during the transfer process and can be applied if only the final state is evaluated. In addition, we proposed and verified a method to reuse the transfer schedule of some wafers when applying the Monte Carlo method. This enables the creation of schedules with short optimization times in sudden changes, such as chamber failure, or when processing large numbers of wafers of the same type.
