Nanoparticles cause wafer yield to decline
Customer pain points:
A 12-inch wafer fab (with a monthly output of 40,000 wafers) faced severe challenges in its 28nm process ultrapure water system.
Particle contamination: 0.1μm particles exceeded the standard in reverse osmosis water, causing photolithography defects and a 3.2% yield loss.
TOC fluctuation: Total organic carbon frequently exceeded the 1ppb threshold, degrading the integrity of the gate oxide layer.
Bacterial growth: Chlorine-resistant bacteria were detected in dead corners of the pipeline, and biofilm caused resistivity fluctuations of 0.1MΩ·cm.
Nano-level precision filtration solutions:
Reconstruction of three-stage filtration system
Components
Technical parameters
Innovation
Carbon Nanotube Pre-Filter
99.9% Removal Rate @1μm, 200m³/h Flux
Conductive Properties Inhibit Biofilm Growth
Ultra-High Molecular Weight RO Membrane
99.9% Salt Rejection Rate, TOC <0.5ppb
Nanogrooving Technology Resists Pollution and Extends Life
Dual-Wavelength UV-TOC Degrader
185nm + 254nm UV, TOC Degradation Rate >95%
Mineralizes Organic Matter to CO₂ + H₂O
Technological breakthroughs:
Zero-dead-zone design: Pipes are fully argon arc welded and electropolished (Ra < 0.4μm) to eliminate bacterial breeding grounds.
AI predictive maintenance: Machine learning algorithms provide 14-day advance warning of membrane contamination, extending cleaning cycles by three times.
Semiconductor compliance certification: Certified to the SEMI F63 ultrapure water standard, meeting process requirements for 28nm and below.
Implementation effect and quantified benefits:
Comparison of key indicators before and after the transformation:
Indicator
Before renovation
After renovation
Improvement
Ultrapure Water Particle Concentration
12 particles/mL @ 0.1μm
2 particles/mL @ 0.1μm
↓83%
TOC Stable Value
0.8-1.5ppb
0.3-0.5ppb
↓65%
Wafer Yield
96.8%
99.2%
↑2.4%
Membrane Replacement Interval
18 months
54 months
↑200%
Economic benefits:
Yield Improvement: 1,280 qualified wafers per month → 128 million yuan in annual value added (unit price: 100,000 yuan per wafer).
Operation and Maintenance Cost Reduction: Extended membrane lifespan saves 3.8 million yuan in annual replacement costs
Water Savings: Recovery rate increased from 75% to 90%, saving 360,000 tons of water annually.
Industry application expansion scenarios:
This solution has been verified to be applicable to:
Photovoltaic cells: Ultrapure water systems in PERC production lines increase conversion efficiency by 0.3% (e.g., at the Longi Ningxia plant).
Display panels: TOC levels in OLED etching water are stabilized to <1 ppb, reducing bright spot defects (BOE Wuhan G10.5).
Biopharmaceuticals: Endotoxin levels in cell culture water are <0.001 EU/mL (Pharmacopoeia Water for Injection standard).