Platform — Module 2

CNN-based defect classification with confidence scoring

Five defect taxonomy categories. Every decision carries a calibrated confidence score. Below-threshold classifications route automatically to human review.

Magnified wafer surface showing defect types with bounding markers

Taxonomy

Five defect categories, classified at inspection speed

Each defect type requires different optical signatures and model training data. Lenspathio's CNN is trained separately on each category — not a generic multi-class classifier.

Type 01

Particle Contamination

Discrete particles from atmospheric deposition, process tool contamination, or substrate handling. Size range: 45nm–50μm. Classified by size, density, and distribution pattern.

Type 02

Scratch Defects

Linear surface damage from wafer handling, cassette contact, or CMP processing. Classified by length, orientation, and depth signature. High correlation with yield loss in logic die layouts.

Type 03 — Critical

Crystal Defects

Stacking faults, dislocations, and etch pits in the crystal lattice. Correlated with epitaxial growth conditions and substrate quality. Classified as critical — flagged for immediate lot hold review.

Type 04

Edge Exclusions

Defects in the 2–5mm edge exclusion zone. Includes edge chipping, residue buildup, and bevel contamination. Significant for compound semiconductor wafers with high bow.

Type 05

Pattern Defects

OPC errors, bridge defects, and overlay shift at the patterned device layer. Detected via comparison to design-rule reference die. Most complex taxonomy — requires process-node-specific training data.

Escalation

Human Review Queue

Any die-level classification below the configurable confidence threshold (default: 85%) routes to human review. Review queue is surfaced to MES with reason code and confidence score — no silent misclassifications.

Architecture

Confidence-calibrated classification

Every die-level classification decision includes a calibrated confidence score. The system is designed to know what it doesn't know.

Configurable threshold

The confidence threshold that triggers human review escalation is configurable per product type. Default: 85%. Logic QA lines typically run 90%. Memory lines where rework cost is lower can run 80%. Tunable per lot type.

Process-node-specific training

Each process node has distinct defect morphology. The model is not retrained on every customer's wafers — it uses optical physics-based synthetic augmentation calibrated to each node's illumination wavelength and pattern pitch.

No cloud training dependency

Model weights are shipped as part of the on-premises deployment package. Updates are delivered via versioned software releases — not pulled from cloud endpoints. Works in fully air-gapped environments.

KLARF defect code mapping

Every defect classification maps to a standard KLARF defect code for compatibility with downstream SEM review workflows. KLARF output is optional alongside SECS/GEM — both can be enabled simultaneously.

See classification results on your wafer data.

The evaluation runs the full classification pipeline on your actual lot. You receive a complete defect taxonomy breakdown, confidence score distribution, and false positive count per category.