Core Viewpoint - The article emphasizes the complexity of water usage in semiconductor manufacturing, highlighting that while fabs consume millions of gallons of water daily, much of it is recycled and reused within the facility, with actual consumption primarily occurring through evaporation in cooling systems [2][3][29]. Water Usage in Semiconductor Fabs - Water is essential for advanced chip architecture, lithography, and backend packaging, serving multiple roles including cooling and waste transport [2]. - The average daily water usage in semiconductor fabs can reach millions of gallons, with cooling towers being the primary source of water loss due to evaporation [2][4]. - In hot and arid regions, evaporation plays a dominant role in water loss, while in cooler climates, the loss is significantly lower [2][4]. Water Management Strategies - Fabs are increasingly implementing smarter wastewater classification, reuse, and heat recovery technologies to reduce water demand [2][5]. - The water intake for a large fab can be equivalent to the water usage of a city with a population of one million, but most of this water is treated and reused within the facility [3][4]. - The water system in modern fabs consists of interconnected cycles, where raw or recycled water is treated to become ultra-pure water (UPW) for wafer processing [4][5]. Reuse and Recycling - Water undergoes multiple usage cycles within the fab, with ultra-pure water typically used only once, while other water types are collected for reuse in less sensitive applications [5][12]. - Companies like UMC have achieved high water recovery rates, with UMC reporting an overall process water recovery rate of 84.3% [12][13]. - The use of recycled water is prioritized, with UMC's Singapore facility using approximately 97.6% recycled water in 2024 [13]. Infrastructure and Planning - Municipal water suppliers must demonstrate their capacity to meet long-term water needs for industrial projects, as seen in Phoenix, Arizona [3][7]. - Effective water management requires long-term planning and infrastructure development to support semiconductor manufacturing [7][8]. Challenges and Innovations - The purity of water is a critical factor that limits reuse; maintaining high purity levels is essential for advanced manufacturing processes [9][10]. - Digital twin technology is being utilized to optimize water and chemical flows, allowing for real-time monitoring and predictive maintenance [16][17]. - The industry faces challenges in measuring persistent chemicals at trillionth-level concentrations, which complicates water management strategies [26][27]. Conclusion - The key issue is not the volume of water used by fabs, but rather how much is recycled and how much is truly consumed, with evaporation being a significant factor in water balance [29]. - Effective water management strategies, including classification, routing, and monitoring, are essential for sustainable semiconductor manufacturing [29].