Most equipment and process engineers become experts at analyzing a wafer map to quickly identify signatures. They can easily identify when their equipment or process was the perpetrator of a maverick yield event. But as defect signatures become more subtle and harder to quickly identify, there is a significant need to consider not just what your in-line inspection systems are identifying, but specifically what they are not identifying.
There is a significant opportunity cost in chasing after weak signatures without ever identifying their root cause. It is now increasingly important to design equipment and processes to be contamination tolerant, providing a robust contamination management strategy to eliminate defects that negatively impact yield and long-term reliability for each process step.