Impact of control plan design on tool risk management: A simulation study in semiconductor manufacturing

In this paper, we analyze the impact of control plan design of defectivity inspections for tool risk management. Defectivity inspections are performed on products and can reveal the yield loss produced by contaminations or structural flaws. The risk considered in this paper concerns the exposure level of wafers on a tool between two defectivity controls. Our goal is to analyze how control plans can impact the manufacturing robustness from the point of view of wafer at risk on tools. A smart sampling strategy is considered for sampling lots to be measured. Actual data from the Rousset fab of STMicroelectronics are used. The simulation experiments are performed using the S5 Simulator developed by EMSE-CMP. Results show that not only the number and positions of controls operations have an important impact on tool risk management, but also how each control operation covers process operations.