Integrated Production Control System in Managing Tool Uptime, Cycle-time and Capacity

In the cycle-time management process of a foundry wafer fab, the most common variability is tool uptime. While it is impossible to let tool continue running without failure, a more precise WIP arrival projection model definitely helps in managing the scheduled down time; and hence the overall uptime performance of the tool. On the other hand, traditional static moves forecast methods do not account for cycle-time commit of individual lots. This may result in a situation where the model is asking for artificially higher equipment uptime than it really requires for a specific period of time (vice versa). This in turn causes unnecessary disruption in equipment maintenance scheduling. In this paper, an integrated production control system to manage cycle-time, moves requirement (capacity) and tool uptime is being introduced. After adopting this system, our fab sees an improvement in the overall "quality moves " produced each day.