Evaluation of a fast defect detection tool to disposition product wafers with large defects in printed photoresist

Summary form only given. KLA-Tencor has installed a new, fast, 50 micron defect detection tool on line at IBM Burlington, staffed by IBM and KLA-Tencor engineers and operators. The KT2401 simultaneously scans entire wafers while storing and presenting a pass/fail recommendation to the operator for review. The KT2401 is used in combination with optical microscope review stations to disposition wafers and diagnose root causes of defects. We evaluated the capability of the KT2401 to: 1) randomly sample the range of products and photo levels; 2) gauge the defects from a targeted tool set; 3) gauge the defects from a targeted process point; 4) quantify the population of photolithography process defects. We describe the potential for process improvements provided by use of the KT2401 by quantifying the rate of rework, the types of defects found, and root causes identified.