Wafer fabrication: realizing 300mm fab productivity improvements through integrated metrology

The operational cost of 300mm wafer production is significantly greater than that of 200mm fabs. Real-time monitoring of product can save time and money through reduced scrap and decreased cycle time. Current process monitoring generally incorporates stand-alone 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 a semi-conductor fab 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. Send-ahead 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 stand-alone metrology via Simulation Modeling.