Particulate Control

Particulate Contamination Control encompasses clean room practices, filtration systems, and procedures designed to minimize particle deposition on semiconductor wafers.

## What Is Particulate Contamination Control?

• Goal: Keep particle counts below critical defect density
• Methods: HEPA/ULPA filtration, clean room protocols, equipment design
• Metrics: Particles per wafer, particles per ft³ of air
• Standard: ISO 14644 defines clean room classifications

## Why Particle Control Matters

At advanced nodes, particles >20nm can cause killer defects. A single particle on a critical layer fails multiple die.

Contamination Control Methods:
| Source | Control Method |
|--------|----------------|
| Air | ULPA filters (99.9995% @ 0.12μm) |
| People | Gowning, airlocks, automation |
| Equipment | Pod-to-pod transfer, mini-environments |
| Process | Wet cleans, megasonic, HF dips |