200mm Fab AMHS improvement during aggressive ramp

The semiconductor industry experienced increased requirements during the period 2008-2010. These requirements were followed by more wafer starts (loading upside). Micron Israel´s 200mm factory capacity increased by more than 40% within one year. The automated material handling system (AMHS) was not originally intended to support a 40% load increase. Prior to the load increase, the 200mm AMHS was not considered a factory constraint. However, after the increase, with the AMHS capacity gap at about 40% of the expected loading, a capacity improvement roadmap was implemented for all toolsets, including the AMHS. This roadmap, among other things, included: optimization of the lot destination, stocker capacity increase, stocker cleaning, and leading parameter definition to prioritize manual handling of lots and route changes. Roadmap action plan priorities were set through simulation gain analysis. All of the AMHS improvements resulted in a system capability increase of more than 20% over the original planned capability. This paper presents a review of the AMHS improvement roadmap actions that led to the system capability increase.