The semiconductor industry drives modern technology, powering everything from smartphones and computers to advanced medical devices and automotive systems. This highly specialized industry heavily relies on chemicals, particularly solvents, in various steps of the process to ensure the quality of devices.
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However, the heavy use of chemicals in this industry is an increasing concern due to safety and environmental risks associated with the types of chemicals used and the manufacturing process. Thus, effective solvent use and solvent management have become critical for the semiconductor industry. In this article, we explore the process of semiconductor manufacturing and in particular, the role of solvents in the process, as well as safer and more sustainable alternatives for the manufacturing process.
The semiconductor manufacturing process involves several complex stages to create integrated circuits (ICs) or chips. The process starts with the deposition and etching of layers of various materials onto a substrate - usually a silicon wafer - to form the desired device structures. Next, these structures undergo a series of processes, including oxidation, photolithography, etching, doping, deposition, chemical-mechanical planarization (CMP), metallization, and various stages of testing. Depending on the type of semiconductor manufactured, there can be between 10 to 100 steps for cleaning alone. This is because the semiconductor needs to be thoroughly cleaned with powerful—and sometimes toxic—chemicals between every step.
Solvents are integral in several stages. For instance, during the wafer preparation, solvents such as acetone or isopropanol are used to remove organic contaminants and particles from the wafer surface before major processing steps. Similarly, in photolithography, solvents are employed to clean surfaces before applying photoresist. Substantial amounts of solvents are also used in etching, deposition, chemical-mechanical planarization (CMP), metallization, and various testing stages.
Solvent use in semiconductor processing comes with contamination risks, which can significantly affect product quality. If the solvents used during critical processes are not adequately purified, they can introduce impurities into the manufacturing process. Even trace levels of contaminants can lead to defects in semiconductor devices, resulting in compromised performance. Maintaining consistent solvent purity is essential to ensuring the reliability and precision of the final products, but it requires robust semiconductor filtration systems and rigorous management.
Solvent use in the semiconductor industry also presents significant health and safety risks to workers. Toxic and volatile solvents can cause various health issues, from skin irritation to severe respiratory problems. Additionally, the flammability of some solvents heightens the danger, making strict safety protocols, proper ventilation, and the use of personal protective equipment (PPE) crucial for safeguarding workers.
Another significant challenge associated with solvent use in the semiconductor industry is its environmental impact. Many solvents used in semiconductor fabrication and manufacturing are volatile organic compounds (VOCs) that contribute to air pollution and environmental degradation. The disposal of spent solvents is also a major concern. Due to their low contamination tolerance, the solvents are often used for single applications, generating large amounts of waste. Moreover, improper disposal can lead to severe soil and water contamination, posing serious risks to ecosystems and public health. To mitigate these impacts, exploring waste management and treatment systems is crucial.
Although separation processes like distillation can manage and recover these solvents, they consume significant energy and contribute significantly to greenhouse gas (GHG) emissions. The substantial energy input required to heat and condense semiconductor solvents releases carbon dioxide (CO2) and other GHGs into the atmosphere. This exacerbates the environmental impact of industrial processes.
Aside from their environmental impact, single-use solvents incur substantial costs, encompassing their purchase, handling, and disposal. The problem does not end upon collection by waste management companies. Roughly 50% of spent solvents are recovered by heat-based separation processes, such as distillation, which consume significant energy for heating and condensing. This further exacerbates the total lifecycle costs and carbon footprint of the solvents.
As global demand for semiconductors continues to grow, the financial sustainability of these practices comes into question. The rising costs associated with solvent use and energy-intensive recovery processes may not be economically sustainable in the long term, and this underscores the need for more energy-efficient and environmentally sustainable solutions in the industry.
SepPure Technologies offers a solution for more sustainable and cost-effective nanofiltration solution to the challenges posted by solvent waste in semiconductor manufacturing. Our advanced membrane-based solvent recovery system, RE(SOLV)®, enables energy-efficient solvent recovery for reclaiming as much as 90% of spent solvents with high level of purity. RE(SOLV)® provides reclaimed solvents with as high as 99.9% purity, allowing the solvents to be reused for numerous processes within semiconductor processes as well as in other adjacent industrial sectors. This innovation cuts waste, greenhouse gas (GHG) emissions, and fresh solvent costs by up to 90%, driving a circular economy and lowering resource depletion and emissions. RE(SOLV)® empowers more energy-efficient semiconductor processes, promotes circularity, and supports both economic and environmental goals of the industry.
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For more information, please visit Semiconductor Solvents.
Semiconductors are essential for our way of life. Without them, our mobile phones, laptops, and cars couldn’t function. They have enabled some of the greatest advances of modern times from the Human Genome Project, to advances in telecommunications and mobile computer technology. The semiconductor industry is a major contributor to the global economy. In the industry had worldwide sales of US$299.5 billion, KPMG estimates that when the effect on the whole electronics value chain is taken into account, the industry enables the generation of the equivalent of 10% of global GDP. Yet despite these benefits, there is a price to pay. Below we highlight eight facts you may not know about the semiconductor industry and its impact and reliance on water.
A semiconductor is a miniaturized electronic circuit containing a multitude of transistors. Water is fundamental to the manufacture of semiconductors. Over a series of steps, semiconductors are built in layers on silicon wafers into integrated circuits (also called microchips). After each one of several dozen layers of semiconductors are added to the silicon wafer, it must be rinsed, requiring massive amounts of water. A great deal of this water is Ultra Pure Water (UPW), water that is thousands of times purer than drinking water. Water so clean, that it is regarded as an industrial solvent. To make 1,000 gallons of UPW takes roughly 1,400 -1,600 gallons of municipal water1.
To create an integrated circuit on a 30cm wafer, can require approximately 2,200 gallons of water; including 1,500 gallons of UPW.2 So a large fabrication facility (Fab) that processes say, 40,000 wafers a month, can use up 4.8 million gallons of water per day, this equates to the annual water consumption of a city of 60,000 people1.Clearly, the manufacture of semiconductors is highly water intensive.
Strangely, despite these substantial levels of water consumption, when the Chinese Ministry of Industry and Information Technology (MIIT) and the Ministry of Water published a notice to further promote water conservation in industry, the semiconductor sector was not included as a priority industry. Industries like iron and steel, textiles, paper, oil refining, food fermentation, and chemicals were on the priority list.
The environmental footprint of the semiconductor industry is even greater as it is also very energy intensive. Fabs can use up to 30-50 megawatts of peak electrical capacity, enough to power a small city.1
Enter the water and energy nexus. In China, 97% of power generation is reliant on water, and the government plans to add a further 1.2TW of water-reliant power by : equivalent to adding the combined total capacity of Australia, UK and the US. This aggressive power capacity build-out will add further stress to water resources, and could leave the semiconductor industry exposed to a potential double whammy of power and water shortages. For more information on China’s water energy issues, please read China: No Water, No Power.
From - China’s semiconductor production achieved a 10-year compounded annual growth rate of 24%. By China controlled 8.6% of the global market share in semiconductors, worth RMB144 billion.3 In China’s semiconductor performance far exceeded the worldwide industry. It’s production revenue grew from $38.1bn in to $43.5bn in for a growth rate of 14.4%; compared to the worldwide semiconductor industry which only grew at a rate of 0.4%.
Source: China’s impact on the semiconductor industry: update, PWC
However, whilst it’s share of global production has risen to approaching 9%, it’s share of semiconductor consumption is much higher. Over the past eight years, China’s share of the worldwide semiconductor consumption market has also grown from less than 19% in to just over 47% in . In fact, in , both China’s semiconductor consumption market and semiconductor industrial growth rates were more than ten times greater than the global industry growth rate.4
This trend of China’s growth in the market is expected to continue; China’s 12th Five-Year Plan has a goal to more than double the size of the semiconductor industry by .
Despite the water intensity of the manufacturing process, a large number of Fabs are located in arid or semi arid regions of the world. Currently 11 of the top 14 semiconductor Fabs in the world are located in the Asia Pacific region, accounting for over 75% of total industry sales.5This inevitably adds further stress to water resources already under pressure from rapid population and economic growth as well as climate change.
Nowhere is this more true than in China, where of the 160 semiconductor wafer fab facilities in operation at the end of , 79 (64% of capacity) were located in the East China or Yangtze River Delta region (Shanghai, Jiangsu from the Dry 11, and Zhejiang from the At Risk 9). The Bohai Ring or North China region, which mainly consists of Beijing,Tianjin, Hebei, Shandong and Liaoning, all part of the Dry 11, accounted for a further 31 Fab’s or 19% of China’s capacity4. For those of you familiar with China Water Risk, these provinces will sound familiar. As can be seen from the maps below, these production hotspots are in areas suffering from water stress through to extreme scarcity, raising questions about future viability in these provinces.
Outside Beijing a large semiconductor trucks in water to the facility several weeks a year and a back-up reservoir is maintained in addition to the municipality’s own reserves. 5 For more on the water disparity between China’s provinces, please review Who’s Running Dry.
Each semiconductor Fab can cost up to US$2.5 billion, a large proportion of this capital expenditure is on water related systems. A UPW system can cost between 1-1.5% of total capital costs around US$25-40 million. The semiconductor industry spends approximately $1 billion on water and wastewater systems and services every year2 Through reduction, reuse and recycling water at semiconductor plants, the industry could save over $100 million per year. 7Effective recycling systems offer a great return on investment: a recent study showed a return on capital investment of five to seven months8.
In addition to recycling, the industry is taking steps to significantly lower the use of UPW through process optimisation. One example is the replacement of wet stations by Automated Wet Benches (AWB) for many wet etching processing steps, resulting in water use reductions of approximately 40%9.
Despite the millions spent on trying to clean up its act, the semiconductor industry in China is suspected of being involved in a large number of environmental violations. The production of semiconductors also utilises a number of chemicals. Because of this, wastewater from Fabs has been found to contain a range of harmful contaminants including arsenic, antimony, hydrogen peroxide, and hydrofluoric acid.
A search of the Institute of Public and Environmental Affairs (IPE) water pollution database reveals over 10,000 environmental violations for key semiconductor companies, over the period -. The IPE database draws on government data.
Historically, semiconductor companies in the US have been subject to litigation linked to groundwater. With the current levels of groundwater pollution in China and ongoing investigations by the MEP, how long will it be before semiconductor companies start finding themselves named and shamed on the MEP’s blacklist? For more on China’s groundwater pollution problems, see here and for more on the MEP’s blacklist of companies, see here.
The semiconductor industry has reportedly been doing a poor job of disclosing water risk to investors.5 The reliability of water supply during the manufacturing process is a major aspect of the industry’s risk profile. The manufacturing cycle for a microprocessor can be between 11-13 weeks, and any forced shutdown during that period will result in all material being lost, effectively wiping out that quarter’s output for the facility. This is particularly worrying considering the location of some of the industry’s major manufacturing sites in water scarce areas.
It is not all bad news however, Toshiba reports a 29% decrease in water use per chip. IBM at its Burlington Vermont plant, through using water conservation technology and advanced analytics, cut water use by 27% and energy bills by US$3 million. At Intel’s plant in Chandler, Arizona, an average of 4 million gallons of water a day is recycled, and through a reverse osmosis treatment plant is able to return drinking quality water back to the municipal supply. In all, through these measures and other water conservation efforts, Intel estimates to have reduced its intake from Chandler’s public water supplies by 80%.8
Water demands for semiconductors are expected to grow as the more complex new generation chips are expected to require up to 1.5 times more water.2What is more with the inbuilt short obsolescence built into modern day electronics and rising prosperity in the developing world for more on this see here and here for more information on this) the semiconductor industry is contributing to the rising e-waste problem and it’s toxic impact on groundwater. It is therefore increasingly important that water risk be made a primary concern, and that the sector as a whole follow leading companies such as Intel (see here) and start investing in water conservation and wastewater treatment technologies, which as shown offer quick returns on capital investment.
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