Defect location accuracy using shape based grouping guided defect centering
Defect location accuracy can be increased using shape based grouping with pattern-based defect centering. Design based grouping of defects on a wafer can be performed. A spatial distribution of the defects around at least one structure on the wafer, such as a predicted hot spot, can be determined. At least one design based defect property for a location around the structure can be determined. The defects within an x-direction threshold and a y-direction threshold of the structure may be prioritized.
1. A method of improving defect location accuracy comprising:
grouping defects on a wafer using a processor, wherein the grouping is based on images of the wafer received at the processor from a wafer inspection tool, wherein the grouping includes associating the defects with an underlying pattern whereby the defects with a same underlying pattern in a vicinity of the defects are classified in a same group;
prioritizing, using the processor, the defects within an x-direction threshold and a y-direction threshold around at least one structure on the wafer, wherein the threshold includes an area larger than the structure;
binning defects at or within the x-direction threshold and the y-direction threshold around the structure as systematic defects and defects outside of the x-direction threshold or the y-direction threshold as nuisance;
correcting, using the processor, a location of a defect using shape based grouping prediction of a probable defect location;
comparing, using the processor, the shape based grouping prediction with a location determined by a degree of scattering of the defects around the structure on the wafer; and
assigning, using the processor, a criticality to the location around the structure.
2. The method of claim 1 , further comprising inspecting the wafer with a wafer inspection tool.
3. The method of claim 1 , wherein the structure is a predicted hot spot on the wafer.
4. The method of claim 1 , further comprising assessing, using the processor, whether one of the defects is a nuisance.
5. The method of claim 1 , further comprising identifying, using the processor, multiple failure mechanisms on the structure.
6. The method of claim 1 , further comprising receiving images of the wafer from a wafer inspection tool at the processor.
7. A system for improving defect location accuracy comprising:
a processor in electronic communication with an electronic data storage unit and a wafer inspection tool, wherein the processor is configured to:
group defects on a wafer based on images of the wafer received at the processor from a wafer inspection tool, wherein the grouping includes associating the defects with an underlying pattern whereby the defects with a same underlying pattern in a vicinity of the defects are classified in a same group;
prioritize the defects within an x-direction threshold and a y-direction threshold around at least one structure on the wafer, wherein the threshold includes an area larger than the structure;
bin defects at or within the x-direction threshold and the y-direction threshold around the structure as systematic defects and defects outside of the x-direction threshold or the y-direction threshold as nuisance;
correct a location of a defect using shape based grouping prediction of a probable defect location;
compare the shape based grouping prediction with a location determined by a degree of scattering of the defects around the structure on the wafer; and
assign a criticality to the location around the structure.
8. The system of claim 7 , wherein the wafer inspection tool is a scanning electron microscope.
9. The system of claim 7 , wherein the processor is further configured to receive the images of the wafer from the wafer inspection tool.
10. The system of claim 7 , wherein the structure is a predicted hot spot on the wafer.
11. The system of claim 7 , wherein the processor is further configured to assess whether one of the defects is a nuisance.
12. The system of claim 7 , wherein the processor is further configured to identify multiple failure mechanisms on the structure.
13. A non-transitory computer-readable storage medium for improving defect location accuracy, comprising one or more programs for executing the following steps on one or more computing devices:
group defects on a wafer based on images of the wafer received at the processor from a wafer inspection tool, wherein the grouping includes associating the defects with an underlying pattern whereby the defects with a same underlying pattern in a vicinity of the defects are classified in a same group;
prioritize the defects within an x-direction threshold and a y-direction threshold around at least one structure on the wafer, wherein the threshold includes an area larger than the structure;
bin defects at or within the x-direction threshold and the y-direction threshold around the structure as systematic defects and defects outside of the x-direction threshold or the y-direction threshold as nuisance;
correct a location of a defect using shape based grouping prediction of a probable defect location;
compare the shape based grouping prediction with a location determined by a degree of scattering of the defects around the structure; and
assign a criticality to the location around the structure.
14. The non-transitory computer-readable storage medium of claim 13 , wherein the structure is a predicted hot spot on the wafer.