Integrated measurement and analysis concept at SMST, a defect management system

SMST (SubMicron Semiconductor Technologies, a Philips and IBM Joint Venture) has established a system for defect management which combines an integration of measurement and analysis tools with the logistics of measurement lots, means same lots and same wafers defect measured at different process levels and finally combined with electrical test data. Through a token ring network defect data from measurement tools are collected, combined and processed for subsequent review and classification. Defect maps and test data are used to drive microscope and SEM stages to take pictures of the defects. Maps and pictures are available inline or at engineer's workplace and provide necessary information for fast decision making, i.e. reaction on tool footprint or recognition as "incoming" problem (short feedback loop). The overlay of inline defect maps and functional test data allows traceability and establishment of FM/yield paretos to define action priorities (long feedback loop).