Local novelty detection against normal wafer micro-patterns
A new local wafer micro-structure may be absent from the known defect set. One class for an entire die hides the novelty location and its relation to the normal pattern.
Preserve the wafer ROI and local score map for review without inferring die electrical performance. Hold the new pattern region until the operator verifies it.
- 01 Normal reference
- 02 New image
- 03 Local comparison
- 04 Score threshold
- 05 Send for review
Select the illustrative reference gallery of normal examples only.
- Local anomaly score
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- Above-threshold area
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- Illustrative score threshold
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Scenes are illustrative simulations; they are not customer references or performance guarantees.
Solution approach
Local features of normal examples are compared with the new ROI. Raw evidence, normal reference and a continuous anomaly map appear separately; the score threshold is not a defect class. Stabilise pattern scale and reveal the normal patch gallery. A continuous local score map marks the micro-pattern novelty.
Process steps
- 01
Normal reference
Select the illustrative reference gallery of normal examples only.
- 02
New image
Image the new sample under the same lighting and registration conditions.
- 03
Local comparison
Show local feature deviation as a continuous heatmap.
- 04
Score threshold
Show the local score and above-threshold area as separate criteria.
- 05
Send for review
Hold an anomalous example for the operator without inventing a defect type.
Related applications
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