Equipment buffering strategy to maximize productivity

In the infancy of 300mm, I300I and J300 adopted a cost-effective 1+1 loadport buffering for most tools with a few exceptions (litho link, implant) where the run-rate and expected utilization of the tool motivated a larger buffer. Metrology tools, inspite of their very high run-rates, were to follow the standard 1+1 configuration due to the cost and footprint impact of additional loadports relative to the expected average utilization. 300mm production experience has shown the need for burst capacity on these tools. This paper explores ways to improve productivity of these tools without compromising cost or footprint goals.