Validating Wafer Cleaning Efficiency with Particle Removal Efficiency (PRE) Testing

In semiconductor manufacturing, every particle matters. Even a single contaminant can cause costly yield losses, especially as device geometries continue to shrink. This makes the ability to measure and validate cleaning process performance not just valuable, but essential.

A recent peer-reviewed study, published in Aerosol Science and Technology offers a clear demonstration of how controlled particles can be used to assess cleaning process efficiency in precision environments. While the research focuses on particle removal in specific cleaning workflows, its findings mirror the challenges faced daily in semiconductor fabs.
 

What the Study Showed

The study examined ways to enhance liquid jet spray cleaning for removing nanoparticle contaminants from silicon wafers which is a critical step in semiconductor manufacturing. While the method is environmentally friendly by avoiding chemicals, it has struggled to effectively remove smaller particles. To overcome this, researchers developed a Monte Carlo model linking single-droplet cleaning theories to real-world, multiple-droplet conditions, enabling accurate predictions of removal efficiency based on particle size and key parameters.

In experiments, the team used a water-spray cleaning system with a two-fluid supersonic nozzle producing 10–40 µm microdroplets at velocities of 14–100 m/s. They found that cleaning time, along with droplet size and velocity, is crucial for maximizing removal efficiency, especially for hard-to-remove 10–30 nm particles. Maintaining a dry surface during cleaning significantly boosted performance, and the model closely matched experimental results. Since ultrafine contaminants strongly adhere to wafer surfaces and resist conventional cleaning, these findings highlight the importance of precise, data-driven evaluation – especially as device geometries shrink and sensitivity to nanoscale contamination grows.
 

Connecting Research to Real-World Fab Operations

In a semiconductor fab, mini-environments and wafer handling tools are vulnerable to particle contamination. The challenge? Particles in the nanometer range can easily escape detection without the right test methods, yet they can cause serious device defects.

This is exactly where MSP’s Particle Removal Efficiency (PRE) testing solution comes in.
 

How MSP PRE Testing Aligns with the Study’s Methodology

• Dry-Deposited PRE Challenge Wafers – Just like the controlled contamination in the study, MSP’s wafers feature precise, repeatable particle deposits, down to sub-micrometer sizes.
• Standardized Testing – Challenge wafers can be used across different cleaning systems, lines or time scales to generate comparable, benchmarkable data to help optimize cleaning settings.
• Wide Process Compatibility – Evaluate everything from cryogenic CO₂ cleaning to UPW rinsing and plasma processes.
• Traceable, Repeatable Results – Generate audit-ready data for internal process control and compliance documentation using consistent baselines.

Benefits for Your Cleaning Process Optimization

With MSP’s PRE testing solutions, you can benchmark new cleaning equipment before full-scale integration, compare different methods side-by-side to find the most effective approach for each contamination type, and proactively address particle risks before they affect yield. By basing improvements on hard data, you can reduce waste, minimize downtime, and ensure your cleaning processes consistently deliver optimal performance.

MSP’s PRE testing solutions bring academic-level precision to fab-floor challenges, enabling engineers to validate cleaning performance with confidence.
 

Learn how MSP PRE Challenge Wafers can help you optimize your cleaning processes and boost yield. Ensure peak wafer cleaning performance with PRE Challenge Wafers!

Explore MSP’s PRE Challenge Wafers