Heaviest only fail potential

Abstract

A method for determining an effective fatal defect count based on defects in a plurality of inspected integrated circuits includes acquiring defect information related to defects in the integrated circuits, and assigning defect weight values to each of the defects based on the defect information. The defect weight values are in N number of defect weight value ranges, including a lowest and a highest defect weight value range. For each integrated circuit, a heaviest defect is determined, where the heaviest defect is the defect on each integrated circuit having a highest defect weight value. For each of the N number of defect weight value ranges, a total number T(n) of the heaviest defects having a defect weight value within a defect weight value range n is determined, where n equals one to N. A weighted total defect count T (n) is determined by weighting the total number T(n) for each of the defect weight value ranges according to a weighting function FP(n) which approaches zero at the lowest defect weight value range and approaches one at the highest defect weight value range. The effective fatal defect count is determined by summing the values of T (n) for the N number of defect weight value ranges. The defect weight values are preferably assigned to each of the defects based on defect size, where the smallest defects are in the lowest defect weight value range, and the largest defects are in the highest defect weight value range. Since the heaviest only weighting gives more weight to large defects, the effective fatal defect count is weighted more heavily toward larger defects.