CYCLE TIME AND YIELD INTERRELATIONSHIP IN WAFER FABRICATION IN-LINE INSPECTION

摘要

This study challenges the common operation management practice that consider CT and Yield separately. We show how the CT versus Throughput curve enables determination of a common yard-stick for CT and Yield. The proposed principle is demonstrated via a specific model that employs this CT and Yield relationship for maximizing wafer fabrication profit. The presented model that integrates economic, production, and process quality facets, is optimally solved versus technology age. The model, although limited, exhibits insightful optimal patterns of CT, Yield, the tradeoff between them, and additional key performance measures. The CT versus Yield tradeoff is greater in the early age and rapidly levels down to a certain constant. In addition, highest profit is gained at early technology age, release rate and utilization increase with age, and inspection frequency decreases with age. In conclusion, this type of integrated CT with Yield modeling can be used to support operation management decisions prior to actual production.