---
language: en
license: mit
library_name: pytorch
tags:
  - image-classification
  - few-shot-learning
  - prototypical-network
  - dinov2
  - semiconductor
  - defect-detection
  - vision-transformer
  - meta-learning
datasets:
  - custom
pipeline_tag: image-classification
model-index:
  - name: semiconductor-defect-classifier
    results:
      - task:
          type: image-classification
          name: Few-Shot Defect Classification
        metrics:
          - name: Accuracy (K=1)
            type: accuracy
            value: 0.995
          - name: Accuracy (K=5)
            type: accuracy
            value: 0.997
          - name: Accuracy (K=20)
            type: accuracy
            value: 0.998
          - name: Macro F1 (K=20)
            type: f1
            value: 0.999
---

# Semiconductor Defect Classifier

**Few-Shot Semiconductor Wafer Defect Classification using DINOv2 ViT-L/14 + Prototypical Network**

Built for the **Intel Semiconductor Solutions Challenge 2026**. Classifies grayscale semiconductor wafer microscopy images into 9 categories (8 defect types + good) using as few as 1-5 reference images per class.

## Model Description

This model combines a **DINOv2 ViT-L/14** backbone (304M parameters, self-supervised pre-training on 142M images) with a **Prototypical Network** classification head. It was trained using episodic meta-learning on the Intel challenge dataset.

### Architecture

```
Input Image (grayscale, up to 7000x5600)
    |
    v
DINOv2 ViT-L/14 Backbone
  - 304M parameters (last 6 blocks fine-tuned)
  - Gradient checkpointing enabled
  - Output: 1024-dim CLS token
    |
    v
3-Layer Projection Head
  - Linear(1024, 768) + LayerNorm + GELU
  - Linear(768, 768) + LayerNorm + GELU
  - Linear(768, 512) + L2 Normalization
    |
    v
Prototypical Classification
  - Cosine similarity with learned temperature
  - Softmax over class prototypes
  - Good-detection gap threshold (0.20)
```

### Key Design Choices

- **DINOv2 backbone**: Self-supervised features transfer exceptionally well to few-shot tasks, even on out-of-distribution semiconductor images
- **Prototypical Network**: Non-parametric classifier that works with any number of support examples (K=1 to K=20+) without retraining
- **Cosine similarity + learned temperature**: More stable than Euclidean distance for high-dimensional embeddings
- **Differential learning rates**: Backbone fine-tuned at 5e-6, projection head at 3e-4 (60x ratio)
- **Gradient checkpointing**: Reduces VRAM from ~24 GB to ~2 GB with minimal speed penalty

## Training Details

### Dataset

Intel Semiconductor Solutions Challenge 2026 dataset:

| Class | Name | Samples | Description |
|-------|------|---------|-------------|
| 0 | Good | 7,135 | Non-defective wafer surface |
| 1 | Defect 1 | 253 | Scratch-type defect |
| 2 | Defect 2 | 178 | Particle contamination |
| 3 | Defect 3 | 9 | Micro-crack (extremely rare) |
| 4 | Defect 4 | 14 | Edge defect (extremely rare) |
| 5 | Defect 5 | 411 | Pattern anomaly |
| 8 | Defect 8 | 803 | Surface roughness |
| 9 | Defect 9 | 319 | Deposition defect |
| 10 | Defect 10 | 674 | Etch residue |

**Note**: Classes 6 and 7 do not exist in the dataset. The extreme class imbalance (793:1 ratio between good and defect3) and visually similar class pairs (defect3/defect9 at 0.963 cosine similarity, defect4/defect8 at 0.889) make this a challenging benchmark.

### Training Configuration

| Parameter | Value |
|-----------|-------|
| Training paradigm | Episodic meta-learning |
| Episodes per epoch | 500 |
| Episode structure | 9-way 5-shot 10-query |
| Optimizer | AdamW |
| Learning rate (head) | 3.0e-4 |
| Learning rate (backbone) | 5.0e-6 |
| LR schedule | Cosine annealing with 5-epoch warmup |
| Weight decay | 1.0e-4 |
| Label smoothing | 0.1 |
| Gradient clipping | Max norm 1.0 |
| Mixed precision | AMP (float16) |
| Batch processing | Gradient checkpointing |
| Early stopping | Patience 20 epochs |
| Input resolution | 518x518 (DINOv2 native) |
| Preprocessing | LongestMaxSize + PadIfNeeded (aspect-ratio preserving) |

### Training Hardware

- **GPU**: NVIDIA RTX PRO 6000 Blackwell Workstation Edition (95.6 GB VRAM)
- **Actual VRAM usage**: ~2 GB (gradient checkpointing)
- **Training time**: ~17 minutes/epoch
- **Convergence**: 7 epochs (early stopping triggered at epoch 27)

## Performance

### K-Shot Classification Accuracy

| K (support images per class) | Accuracy |
|------------------------------|----------|
| K=1 | 99.5% |
| K=3 | 99.7% |
| K=5 | 99.7% |
| K=10 | 99.7% |
| K=20 | 99.8% |

### Per-Class F1 Scores (K=20)

| Class | F1 Score |
|-------|----------|
| Defect 1 (Scratch) | 1.000 |
| Defect 2 (Particle) | 1.000 |
| Defect 3 (Micro-crack) | 1.000 |
| Defect 4 (Edge) | 1.000 |
| Defect 5 (Pattern) | 0.994 |
| Defect 8 (Roughness) | 1.000 |
| Defect 9 (Deposition) | 1.000 |
| Defect 10 (Etch residue) | 0.996 |

**Balanced accuracy (K=20)**: 0.999
**Macro F1 (K=20)**: 0.999

### Good Image Detection

The model includes a cosine similarity gap threshold for detecting non-defective ("good") wafer images:

| Metric | Value |
|--------|-------|
| Good image accuracy | ~90% |
| Defect image accuracy | ~97% |
| Gap threshold | 0.20 |

## How to Use

### Quick Start

```python
import torch
import yaml
from PIL import Image
from problem_a.src.backbone import get_backbone
from problem_a.src.protonet import PrototypicalNetwork, IncrementalPrototypeTracker
from problem_a.src.augmentations import get_eval_transform

# Load model
with open('problem_a/configs/default.yaml') as f:
    cfg = yaml.safe_load(f)

backbone = get_backbone(cfg['model']['backbone'], cfg['model']['backbone_size'])
model = PrototypicalNetwork(backbone, cfg['model']['proj_hidden'], cfg['model']['proj_dim'])

checkpoint = torch.load('best_model.pt', map_location='cpu', weights_only=False)
model.load_state_dict(checkpoint['model_state_dict'])
model.eval().cuda()

transform = get_eval_transform(cfg['data']['img_size'])

# Create tracker and add support images
tracker = IncrementalPrototypeTracker(model, torch.device('cuda'))

# Add support images (at least 1 per class)
for class_id, image_path in support_images:
    img = Image.open(image_path).convert('L')
    tensor = transform(img)
    tracker.add_example(tensor, class_id)

# Classify a query image
query_img = Image.open('query.png').convert('L')
query_tensor = transform(query_img).unsqueeze(0).cuda()

with torch.no_grad():
    log_probs = model.classify(query_tensor, tracker.prototypes)
    probs = torch.exp(log_probs).squeeze(0)

# Get prediction
label_map = tracker.label_map
reverse_map = {v: k for k, v in label_map.items()}
pred_idx = probs.argmax().item()
predicted_class = reverse_map[pred_idx]
confidence = probs[pred_idx].item()
print(f'Predicted: class {predicted_class}, confidence: {confidence:.3f}')
```

### Download with huggingface_hub

```python
from huggingface_hub import hf_hub_download

checkpoint_path = hf_hub_download(
    repo_id="Makatia/semiconductor-defect-classifier",
    filename="best_model.pt"
)
```

## Model Specifications

| Property | Value |
|----------|-------|
| Architecture | DINOv2 ViT-L/14 + Prototypical Network |
| Total parameters | 306,142,209 |
| Trainable parameters | 77,366,273 (25.3%) |
| Backbone | DINOv2 ViT-L/14 (frozen + last 6 blocks) |
| Embedding dimension | 512 (L2-normalized) |
| Projection head | 1024 -> 768 -> 768 -> 512 |
| Input size | 518x518 (aspect-ratio preserved with padding) |
| Input channels | Grayscale (converted to 3-channel internally) |
| Inference time | ~700ms (GPU) / ~3s (CPU) |
| VRAM (inference) | ~2 GB |
| Checkpoint size | 1.17 GB |
| Framework | PyTorch 2.0+ |
| Dependencies | timm >= 1.0, albumentations >= 1.3 |

## Checkpoint Contents

The `.pt` file contains:

```python
{
    'epoch': 7,                    # Best epoch
    'model_state_dict': {...},     # Full model weights
    'best_val_acc': 0.906,         # Validation accuracy (episodic)
    'config': {...},               # Training configuration
}
```

## Intended Use

- **Primary use**: Semiconductor wafer defect detection and classification in manufacturing quality control
- **Few-shot scenarios**: When only 1-20 labeled examples per defect class are available
- **Research**: Few-shot learning, meta-learning, and industrial defect detection benchmarks

## Limitations

- Trained specifically on Intel challenge semiconductor images; may need fine-tuning for other semiconductor processes
- Good image detection (~90% accuracy) is less reliable than defect classification (97-100%)
- Requires grayscale input images; color images should be converted before inference
- Extremely rare classes (defect3: 9 samples, defect4: 14 samples) have lower representation in training

## Source Code

Full training pipeline, evaluation scripts, and PySide6/QML desktop application available at:
[github.com/fidel-makatia/Semiconductor_Defect_Classification_model](https://github.com/fidel-makatia/Semiconductor_Defect_Classification_model)

## Citation

```bibtex
@misc{makatia2026semiconductor,
  title={Few-Shot Semiconductor Defect Classification with DINOv2 and Prototypical Networks},
  author={Fidel Makatia},
  year={2026},
  howpublished={Intel Semiconductor Solutions Challenge 2026},
}
```

## License

MIT License