Risk Based Capacity Planning Method for Semiconductor Fab with Queue Time Constraints

It is difficult to plan capacities of a semiconductor wafer fabrication with constraints of queue time which means a waiting time from the end of a step to the start of the next step for warranting production quality. If the queue time constraints could not be kept, the product is scrapped or reprocessed for qualitative recovery, and production efficiency remarkably decreases. This paper proposes an evaluation method which enables capacity planning of a fab with the queue time constraints, and shows its validity by simulation experiments. Furthermore we present an effectiveness of the method by applying to actual production lines.