Field test results of an automated image retrieval system

The rapid identification of yield detracting mechanisms through integrated yield management is the primary goal of defect sourcing and yield learning. At future technology nodes, yield learning must proceed at an accelerated rate to maintain current defect sourcing cycle times despite the growth in circuit complexity and the amount of data acquired on a given wafer lot. As integrated circuit fabrication processes increase in complexity, it has been determined that data collection, retention, and retrieval rates will continue to increase at an alarming rate. Oak Ridge National Laboratory (ORNL) has been working with International SEMATECH (ISMT) to develop methods for managing the large volumes of image data that are being generated to monitor the status of the manufacturing process (Tobin et al, 1999 and 2000). This data contains an historical record that can be used to assist the yield engineer in the rapid resolution of manufacturing problems. To date, there are no efficient methods of sorting and analyzing the vast repositories of imagery collected by off-line review tools for failure analysis, particle monitoring, line width control, and overlay metrology. In this paper, we describe a new method for organizing, searching, and retrieving defect imagery based on visual similarity. The results of an industry field test of the ORNL image management system at two independent manufacturing sites are also described.