Semiconductor Etching Circulating Cooling Water Treatment: Project and Technical Overview

A Comprehensive Solution for Precision Manufacturing

In semiconductor wafer fabrication, etching processes represent a core link in micro-nano precision manufacturing. During continuous process operation, etching equipment generates substantial circulating cooling water discharge. Water quality directly impacts equipment stability and product yield. Introducing a recent project for semiconductor etching circulating cooling water treatment, delivering an efficient, integrated, and intelligent solution tailored for semiconductor wafer fabrication facilities.

Industry Challenges in Etching Process Cooling Water Treatment

Semiconductor etching equipment imposes stringent requirements on cooling water purity, temperature stability, and particulate content. Based on wastewater characteristics, the effluent can be classified into two distinct quality categories:

• High-turbidity corrosive process wastewatercontains complex components including Suspended Solids (SS), fluoride ions, and heavy metals such as tungsten. This stream exhibits high turbidity, strong corrosivity, and risks of heavy metal precipitation.

• Low-turbidity circulating cooling water primarily contains fine suspended particulates as the main contaminant.

If contaminants are not effectively removed, long-term operation can lead to pipeline scaling, media channel blockage, electrochemical corrosion, and pitting. These issues cause degradation of heat exchange efficiency in etching equipment, damage to precision chambers and heat exchange pipelines, and in severe cases, unplanned production line shutdowns—directly impacting Fab facility yield rates and production continuity.

Differentiated Treatment Approach

To address varying water quality conditions in semiconductor wafer fabrication, a differentiated treatment strategy is employed, matching actual discharge water quality and flow fluctuations of each client's facility.

• High-Turbidity Tungsten- and Fluoride-Containing Corrosive Wastewater: Lamella Sedimentation Separation

For high-turbidity, highly corrosive process wastewater containing tungsten and fluoride, an inclined plate Lamella Clarifier for sedimentation separation system is utilized, equipped with coagulation reaction units. Through chemical dosing, the system achieves colloidal destabilization, heavy metal co-precipitation, and calcium salt precipitation of fluoride ions. This effectively removes SS, fluorides, and heavy metal contaminants from the water stream, reducing corrosive factors and scaling ion loads to protect downstream process systems and heat exchange equipment.

• Low-Turbidity Circulating Cooling Water: Hydrocyclone Separation and Filtration

For low-turbidity circulating cooling water, a hydrocyclone separation + precision filtration combination processis deployed. The system uses centrifugal force to efficiently separate and remove solid particles of 50μm and larger, as well as abrasive impurities. Effluent quality is monitored online, meeting both in-plant water reuse and Discharge Standards, enabling water resource recovery.

System Configuration

The complete system integrates eight modules: wastewater collection, coagulation reaction, Lamella sedimentation, hydrocyclone separation, precision filtration, circulating cooling, water reuse, and intelligent chemical dosing. The compact footprint is designed to fit within the limited utility space typical of semiconductor fabrication facilities.

System Advantages

• Highly Integrated Design for Space Efficiency

Equipment is modularly integrated with a small overall footprint, suitable for the compact utility spaces of Fab facilities. This design accommodates both new production lines and retrofit/expansion scenarios for existing lines.

• Fully Automated Operation for 24/7 Continuous Production

A PLC-based control system enables online water quality monitoring, automated chemical dosing, and interlocked sludge discharge and backwashing. The system supports 24-hour unattended operation, matching the continuous production mode of semiconductor factories and minimizing process fluctuation risks from human intervention.

• Factory Prefabricated for Rapid Skid-Mounted Deployment

Equipment is factory prefabricated and skid-mounted, requiring only on-site pipeline connections. This approach significantly shortens installation and commissioning cycles, enabling rapid integration into facility drainage systems and accelerating project completion.

• User-Friendly Operation and Reduced OPEX

The human-machine interface is intuitive, and system interlock protection is comprehensive. Optimized consumable parts design reduces maintenance workload, effectively lowering facility operation and maintenance costs for both labor and spare parts consumption.

• Water Recycling for Cost Reduction and Carbon Footprint Minimization

Treated wastewater can be returned to the in-plant circulating water system, reducing wastewater discharge and fresh water demand. This approach lowers sewage treatment costs while supporting corporate compliance with semiconductor industry water conservation, carbon reduction, and environmental regulatory requirements—achieving comprehensive production cost reduction and efficiency improvement.

Conclusion

Semiconductor etching circulating cooling water treatment directly impacts equipment service life, process yield, and production line continuity. The Shanghai Lingang project demonstrates a comprehensive cooling water treatment system solution based on differentiated treatment, high-efficiency sedimentation, hydrocyclone filtration, and intelligent control—providing semiconductor wafer fabrication facilities with a safe, reliable, and cost-effective approach to critical water treatment challenges.