Modified process control chart in IC fabrication using clustering analysis

During the complicated production process in integrated circuit (IC) fabrication, various types of defects on a wafer surface are unavoidable. As the wafer size increases, the clustering phenomenon of the defects becomes increasingly apparent. To upgrade IC products' yield and reliability, statistical process control is feasible for tracking a manufacturing process. However, the clustered defects frequently cause many false alarms when the standard control charts for defects are used. In this study, we present a method for constructing defect control charts in processes that yield clustered defects. A case study is also evaluated, indicating that the proposed method produces satisfactory control charts for the defect data in IC fabrication.