Methods to Quantify the Detection Probability of Killing Defects

Two methods are presented to quantify the killing defect detection probability, or capture rate, of inline defect inspections. The first method uses yield impact and kill ratio of defects above a given size. By comparing the theoretical, critical-area based dependence between the yield impact and the kill ratio of defects above a given size, with the dependence as found from defect–yield correlation on product wafers, an estimate can be made of the fraction of yield impact explained by detected defects. The second method uses conventional defect–yield correlation. By plotting wafer level yield of clean die against the yield impact found by defect–yield correlation, it is possible to estimate the yield impact of undetected defects.