Realizing 300 mm fab productivity improvements through integrated metrology

The operational cost of 300 mm wafer production is significantly greater than that of 200 mm fabrications. Real-time monitoring of product can save time and money through reduced scrap and decreased cycle time. Current process monitoring generally incorporates standalone metrology, which is time consuming and requires excessive wafer handling by production operators. The benefits of integrated metrology are measured by considering the impact of metrology on semiconductor fabrication through simulation modeling. Since the process and metrology steps are in series, overall process throughput depends on metrology methods. Furthermore, the measurements impact WIP (work in process) inventory. WIP is at risk if the process drifts. Sendahead samples reduce WIP risk but also reduce process throughput and tool utilization. Integrated metrology minimizes risk but may decrease throughput rate. This paper explores the operational benefits of integrated metrology strategies versus standalone metrology via simulation modeling.