Semiconductor Wastewater: Its Challenges, Solutions, and Opportunities

Whether they’re connecting phones and laptops or traditionally analog products like cars, semiconductors are a cornerstone of our digital world. As the burgeoning fields of the Internet of Things (IoT) and Artificial Intelligence (AI) become integrated into our everyday lives, the over $500 billion semiconductor industry will likely maintain its relevance for decades to come.?

However, this surge in semiconductor demand comes with a parallel thirst for ultrapure water (UPW) and a burden of hard-to-treat semiconductor fabrication and packaging wastewater encumbered by a diverse group of chemicals and contaminants. These processes, spanning from wafer manufacturing and etching to deposition and ion implantation, require significant volumes of UPW and produce toxic wastewater that strains already scarce water supplies amid climate change and growing demand.

Equipped with experienced engineers, contractors, and proprietary treatment systems, BW Water is a go-to partner for semiconductor facilities grappling with these complex wastewaters. We offer innovative solutions that transform semiconductor wastewater into reuse water, recover valuable resources, and ensure environmental compliance.?

Semiconductor Wastewater Characteristics

The semiconductor industry relies on UPW and other high-quality process waters for critical manufacturing processes, like chemical-mechanical polishing and wafer fabrication. The fabrication process uses around 67% of a manufacturing plant’s water budget; the other 33% involves cooling, exhaust scrubbers, and humidification. At the end of each stage, wash water carries the remaining solvents, metals, and organics away from the wafer for wastewater treatment.

This incongruous mixture of contaminants generates a complex, toxic wastewater. Notably, silicon wafer waste streams can include hazardous yet valuable materials such as crystalline silicon sludge, hydrofluoric acid, and copper. Isopropyl alcohol (IPA) is extensively used across multiple production stages for cleaning and disinfection, spiking the chemical oxygen demand of this hard-to-treat wastewater. The diverse nature of these contaminants renders conventional biological wastewater treatment methods ineffective, creating the need for specialized and advanced treatment solutions.

Pain Points

This variety of contaminants makes treatment challenging and costly, as each contaminant type—ranging from surfactants and metals to volatile organics—requires a tailored solution to precipitate metals and chemicals, regulate pH, and remove fluoride and ammonia. Additionally, the irregular flow and fluctuating concentrations of these wastewater streams also pose particular operational challenges for the control of the systems, which are typical of complex production processes.

Because of this need for tailored treatment solutions, semiconductor wastewater skids quickly consume precious capital expenses, operations expenses, and facility footprints in order to comply with local environmental regulations and potentially reuse water. Facilities must also consistently stay up to date with ever-changing regulations that can complicate treatment processes that historically met standards.

Internal changes to the fabrication and packaging stages of semiconductor manufacturing can also affect the cost and operability of the wastewater system. The semiconductor industry evolves constantly, creating downstream effects on wastewater operations and requiring new operating procedures.?

However, with the right partner, semiconductor manufacturers can optimize the cost, performance, and space requirements of their treatment solutions.

Treatment, Reuse, Recovery

Understanding the problem is the beginning of every solution. One must survey a semiconductor site’s wastewater characteristics to diagnose the necessary treatment methods, realistic efficiency rates, and process limitations. Once these are established, experienced designers and technology providers can guide the way.

Strategically pairing source points and reuse applications is crucial for organizations aiming to reuse wastewater. For example, those who want to reuse wastewater as UPW would be recommended to source water from cleaner stages of the fabrication process that don’t have heavy contaminant loads. Matching sources and applications can make reuse treatment cost-effective. More heavily contaminated wastewater can still be treated to reuse standards but may be better suited for cooling tower condensate or exhaust scrubbing.

Moreover, the recovery of contaminants like silicon, fluoride, copper, and IPA can effectively remove these contaminants from wastewater and offer a potential revenue stream to semiconductor manufacturers by selling or reusing recovered metals and materials. Resource recovery can limit consumables costs at manufacturing sites and divert these valuable yet toxic materials from rivers and lakes. The practice requires additional equipment but can pay for itself based on the value of what is recovered.

BW Water designs and builds treatment technologies that can handle inconsistent flows, heavy contaminant loading, and adapt to new process requirements. Our expertise extends from designing and constructing these solutions to fully automating wastewater stages like hydrofluoric acid treatment.?

Conclusion

The semiconductor industry faces intricate financial and regulatory challenges in wastewater management, necessitating advanced treatment solutions. BW Water can be a crucial partner to semiconductor manufacturers, offering wastewater expertise and sophisticated technologies tailored to efficiently treat and reuse semiconductor wastewater. With the right system, meeting environmental regulations becomes easier and can support sustainability through water reuse and resource recovery.?

For a deeper dive into how BW Water can assist your facility in overcoming wastewater treatment challenges, visit our website or contact us for more comprehensive details on industrial wastewater solutions.