Using natural statistics concept to develop a capacity model that can solve tool-operation multi-to-multi relation of IC FAB

Capacity management is a crucial issue of Fab production due to its highly running cost. We can have many software packages to help us to calculate the Fab capacity in commercial market. However, unfortunately, few of them can fulfill the requirement of our changing situation. In the real world, the relationship between the operations and tools is a complex, many-to-many interaction. Furthermore, sometimes we may find the WPH (wafer per hour) of same recipe varied from tool to tool. Those realities make it difficult to compute tool loading and throughput. This paper describes a model based on our innovative methodology, "the natural statistic concept", to solve such problem. This model not only can provide a useful methodology to solve the calculation issues but also give us useful information for tool capacity management. It is simple and effective. Most of all, we can develop and process it, simply by using of Excel and VBA programs.