Method of defect review
View Patent ↗A method of defect review. First, a wafer with a plurality of defects is provided. A defect inspection is performed to detect the defects. An automatic defect classification is then performed to divide the defects into different defect types according to a predetermined database. A defect review is performed to review different defect types of defects which are sampled in different weights according to yield killing ratios of each defect types.
1. A method of defect review comprising following steps:
providing a wafer with a plurality of defects;
performing a defect inspection to detect the defects;
performing an automatic defect classification according to a database to separate the defects into a plurality of defect types;
adjusting sampling ratios according to an influence degree each defect type has on process yield; and
performing a defect review using the adjusted sampling ratios.
2. The method of claim 1 wherein the database comprises information about the plurality of defect types and defect information corresponding to each defect type.
3. The method of claim 2 wherein the defect information comprises the influence degree of the process yield of each defect type.
4. The method of claim 3 wherein the database separates the defect types into killer defects and non-killer defects according to the influence degree of the process yield.
5. The method of claim 4 wherein the sampling ratio of the killer defects in the defect review is larger than that of the non-killer defects.
6. The method of claim 3 wherein the database separates the defects into pre-layer defects and adding defects, and further separates the adding defects into killer defects and non-killer defects.
7. The method of claim 6 wherein the defect review focuses on the adding defects.
8. The method of claim 1 wherein after finishing the defect inspection, a judgment of cluster defects is performed and a defect review with a high sampling ratio is performed on the cluster defects if the cluster defects exist.
9. The method of claim 1 wherein the database is updated according to the result of the defect review after finishing the defect review.