Identifying capacity loss due to operational work methods

A new semiconductor manufacturing line costs in excess of Θ to build and equip. Because of these high costs, it is imperative that all components of capacity loss be identified and understood. Traditionally, much emphasis has been placed on understanding the contribution of tool non-availability to capacity loss. There has been considerable attention paid by engineering and maintenance to identifying and improving these loss components. However, significant capacity loss can also occur when a production operator is not available to attend a tool in a timely fashion to load and unload lots. This paper discusses an analysis that identifies and quantifies the capacity loss caused by operator unavailability for a specific tool set, i.e., CVD tungsten and HDP deposition tools. A multiobservational study was used as the specific technique to examine the performance of the tool set. The analysis included an examination of operator head count, activity, and coverage. The study showed a significant loss because of operator non-availability and identified specific work methods that contributed to this loss. The results were then used to suggest modifications to these work methods to reduce the amount of capacity lost