Water is an essential resource. Not only for our planet, but also for the technology we create. In fact, water and water management are crucial for the semiconductor industry. While many might not know it, the production of semiconductors requires a large amount of water, that left unregulated, can contribute to pollution and waste.
In the semiconductor manufacturing process, we rely on “Ultra-Pure Water,” or UPW, that is free of all ions, particles, chlorine or silica to produce semiconductor that are free of contaminants. Once used, this water is discharged from the system as “wastewater” that must be treated and properly discharged – or reused.
That’s why the use, reuse, treatment and effluent of water is an important issue for SK hynix, especially as demand for semiconductors continues to grow around the world.
For SK hynix, water management is a serious commitment that spans across our global network. SK hynix currently operates four sites in South Korea and China, and plans to establish another in Yongin, South Korea to accommodate the ever-growing demand for semiconductors.
Types and Definition of Water in the Semiconductor Industry
Water management in the semiconductor manufacturing industry can be classified into three areas:
1. Water-for-use: Manages proper quality and quantity of supply water quality for semiconductor manufacturing processes.
2. Wastewater management: Treats wastewater discharged from processes and facilities.
3. Recycle water: Secures industrial water effectively.
Water-for-use can be defined as “water used for a specific purpose” and there may be a difference in the quality of the water supplied according to the purpose of use. In the semiconductor industry, it is often classified into UPW, industrial water (water required for facilities), and residential water – which are all treated and supplied according to the properties of each water.
The water supply line of the SK hynix headquarters in Icheon is being operated in a dual system. Two water intake sources including the water pipe network from the Korea Water Resources Corporation (K-water) are being operated stably. Through this, SK hynix is securing the stability of the water supply.
Figure 1. Water-for-use Process
Wastewater can be defined as “water that cannot be used as it is, due to the liquid or solid water contaminants thereof.” In the semiconductor industry, wastewater is typically generated after the treatment of contaminants in the wafer cleaning process and air pollution prevention facility.
For wastewater treatment, SK hynix is operating a treatment system that includes advanced treatment such as activated carbon and a total phosphorous removing apparatus.
Recycle water can be defined as the water used for residential and industrial purposes, after being treated in facilities that make the sewage and wastewater reusable. In the semiconductor industry, water generated during the process is mainly treated and reused after securing the required water quality according to the place of use.
The water used, recycled, and circulated by SK hynix can be explained in Figure 2 below.
Figure 2. Diagram of Water Flow at SK hynix’s sites
Figure 3. Reverse osmosis system
Ultra-Pure Water (UPW) is water that has been purified to very strict specifications and is used primarily in the semiconductor and pharmaceutical industries. The wastewater recycling system re-supplies the wastewater by treating it to the level of industrial water through the Ultra-Filtration (UF)1 and Reverse Osmosis (RO)2 processes in the wastewater treatment plant. The recycle water is supplied by classifying the supply destinations according to the required water quality. The UF is a filter treatment method that filters the water up to 2nm. The RO method is a process for obtaining clean water through a pressure stronger than the osmotic pressure and is mainly used when purifying seawater.
Figure 4. Water Recycle System of SK hynix
Water Management Strategy and Goals of SK hynix
Semiconductors are a mainstay of the larger electronics industry, providing an essential function for many of the electronic devices we rely on every day.
As demand for semiconductors grows, so do the pressures on water usage, treatment and management within the industry. To rise to the challenge, SK hynix has established a series of initiatives to reclaim used wastewater, reduce waste and improve efficiency.
Through the Life Cycle Assessment (LCA)3, SK hynix also plans to expand the eco-friendly product certification by evaluating and improving the water consumption and environmental impact in the entire product life cycle.
SK hynix plans to formulate “the definition of water in the semiconductor industry” through the World Semiconductor Council (WSC) and lead a joint effort towards water reclamation.
By 2021, SK hynix plans to improve the quality of discharged water by integrating wastewater that has been treated and discharged from some aged wastewater treatment facilities into an advanced integrated wastewater treatment facility. By 2022, The Company aims to reclaim an average of 62,000 tons of water per day on sites in South Korea.
Biochemical Oxygen Demand (BOD), the main water quality index among legal standards, is managed within 10% compared to legal standards which is 30mg/ℓ (legal standard 30mg/ℓ, company standard 2.4mg/ℓ), and investment and maintenance are being promoted.
SK hynix is confident it will achieve these goals by establishing a recycle system at the rear end of the wastewater treatment plant and the forming a company-wide used water and wastewater reduction Task Force Team. We strive to maintain a healthy balance between economic and social values, and it is why we believe in creating technology for a better world.
Figure 5. (Left) Jang Hwan Moon TL / Environment Management Team,
(Center) No Hyeok Park Team Leader / Environment Management Team,
(Right) Hyuk Hwa Kwon TL / CR Team
1RO is a method of obtaining clean water through a pressure stronger than osmotic pressure. This method is mainly used for purifying seawater and can be used as an advanced water treatment system.
2UF is a filtering device that filters up to 2nm. This plays the role of screening before entering the RO system
3Life Cycle Assessment (LCA) is a method of evaluating the environmental impact in consideration of the entire life cycle of the evaluated product. By using this method, the Company has been obtaining carbon/water footprint certification. LCA is a method for assessing the environmental impact of the entire life cycle of a product.
