In this paper, a new methodology for effective process excursion monitoring
using defect review/classification information is proposed. We introduce a
new defect classification scheme, in which relevant defect types that are
likely to be caused by the same mechanism or source are grouped into a "def
ect family." It is demonstrated that trending by the defect family drastica
lly improves the detection efficiency of killer defect excursion by reducin
g or eliminating noise resulting from irrelevant benign defects. We compare
the risks of missing critical excursions for monitoring by total defect co
unt, killer defect count, and killer defect family, and illustrate the effe
ctiveness of our methodology using data from actual fabline.