Ensuring Purity at the Nanometer Scale: A Quality Control Imperative for Semiconductor Chemical Suppliers
A Guide for Quality Control Engineers
As semiconductor devices scale down to sub-10 nm nodes, the margin for error in chemical purity shrinks dramatically. For quality control engineers working with chemical suppliers, ensuring ultra-clean process chemicals is no longer optional—it’s mission-critical.
Why Particle Control Matters
Modern semiconductor manufacturing demands chemical purity at levels previously unattainable. Traditional particle counters, limited to detecting particles ≥30–40 nm, fall short of today’s requirements. The Chem 20™ chemical particle counter bridges this gap with 20 nm sensitivity, and 9 nm for metallic particles, enabling real-time, actionable data across a wide range of high-purity chemical applications.
Inline Verification Before Dispatch
Chemical suppliers now rely on the Chem 20 to verify particle levels immediately before product dispatch. Measurements are taken at the cleanest inline sample point—just before chemicals are filled into shipping containers. This ensures that the product meets stringent purity standards before leaving the facility.
A secondary post-fill measurement—performed after pressurizing the container and sampling the chemical—reveals contamination introduced during the filling process or from the container’s internal surfaces. These tests often uncover significant variability in container cleanliness, highlighting the importance of container qualification in quality control.
Supplier Benchmarking
Semiconductor manufacturers use the Chem 20 to compare incoming chemical deliveries from different suppliers. In one study, Supplier A’s sulphuric acid showed an order of magnitude more 20 nm particles than Supplier B’s, despite similar performance at larger particle sizes. This underscores the importance of sub-70 nm particle detection in supplier evaluation.
Filter Performance and Aging
Quality control engineers must also monitor the performance of particle filters used in chemical systems. Chem 20 data reveals that:
- New filters may release particles during initial wetting and require time to stabilize.
- Older filters, though rated for larger particles, may outperform newer ones due to accumulated particulate matter enhancing retention.
- Real-time monitoring helps determine when filters are ready for production or nearing end-of-life.
Practical Applications
- Filter Wetting Protocols: Chem 20 data supports efficient wetting procedures using IPA/water solutions, ensuring filters are clean before use.
- Mask-Blank Cleaning: Chem 20 measurements help validate the effectiveness of cleaning fluids and filters used in photomask preparation, a critical step in pattern transfer.
