Defect Detection & Classification
Production Systems
ADC systems, integration with inspection tools, and continuous learning
Automatic Defect Classification (ADC)
Automatic Defect Classification (ADC)
ADC systems automatically classify defects in real-time as part of the production inspection flow:
- Inline ADC: Classification happens on the inspection/review tool itself, immediately after image capture. Low latency but limited compute.
- Offline ADC: Images are transferred to a server for classification by more sophisticated models. Higher accuracy but adds delay.
- Hybrid: Fast pre-classification inline, with uncertain cases sent to a more powerful offline system.
Production ADC requirements:
- Speed: Classify 1,000+ defects per wafer in seconds
- Accuracy: >95% agreement with expert human classification
- Purity: Critical defect categories (e.g., "killer defect") must have very high precision — false negatives are costly
- Adaptability: Models must handle new defect types as processes change
Key Concept: Continuous Learning
Semiconductor processes constantly evolve — new recipes, new materials, new pattern densities. ADC models must be continuously updated with new training data. This requires a pipeline: flag uncertain classifications → expert review → relabel → retrain → redeploy. Active learning prioritizes the most informative samples for human review.
Knowledge Check
Knowledge Check
1 / 1What is the key challenge for ADC systems in production?