Water Management Innovation Critical to the Future of ICs

Article By : Arthur Chuang, TSMC

That water is in short supply is not news, but things are set to get more challenging.

That water is in short supply is not news, but things are set to get more challenging. Close to 2.4 billion people already live in “water scarce” areas, according to the World Data Lab, which operates the Water Scarcity Clock. The United Nations notes that by 2030, lack of access to water could displace up to 700 million people. Indeed, Taiwan, the home of TSMC, is currently in the grip of its own water crisis as it experiences its worst drought in over half a century. We can only assume that this scenario will become more commonplace.

TSMC’s daily water consumption, compared to the amount of water available on a daily basis, by site. (Click on the image for a larger view)

What is important is how we respond. As makers of semiconductors, we are essential to modern life. Water is also an essential element to chip manufacturing. According to Water Technology, a fabrication plant gets through anywhere between two and four million gallons per day to clean silicon wafers and cool equipment. To reduce the amount of water used, we must rise to the challenge with a spirit of innovation and collaboration, as well as solid risk management.

TSMC has a long-established Enterprise Risk Management system in place, which covers water supply risks. TSMC has identified and ranked climate-related risks and opportunities by following the Task Force on Climate-related Financial Disclosures (TCFD). We also have detailed response procedures to handle water shortages at different stages.

Evolution presents an opportunity for such innovation. As semiconductor technology advances, the use of chemicals and the complexity of manufacturing increases. This calls for a higher quantity and quality of purified water, which has implications for energy usage as well as water supply. Demand for semiconductors is only going to increase. Even as output rises, we must continue to develop ways to reduce water consumption in parallel for our industry to remain sustainable. We cannot ignore any chance to conserve water efficiently, no matter how small it might seem.

To this end, TSMC treats water source management as a production cost. Reclaimed water is our most significant water source (between 85% and 90%). In 2020, TSMC launched a program to build the “TSMC S.T.S.P. Reclaimed Water Plant,” the first privately-owned water reclaimed plant in Taiwan. From an initial daily recycling capacity of 5,000 CMD of water, we aim to regenerate 20,000 CMD per day by 2023.

Water management systems at TSMC.

As well as recycling the water we use, it is essential that we continue to find ways to reduce or avoid the use of toxic solvents in the manufacturing process. We have eradicated NMP (N-methylpyrrolidone) from the wafer cleaning process, and operate a wastewater drain segregation system based on characteristics and concentration. We prohibit the use of any chemicals that cannot be broken down or removed from the water.

Of course, water purification represents a separate challenge in terms of energy consumption, but there are ways to minimize it. We have benefited from the adoption of high-efficiency IE3 and IE4 motors and heat recovery devices, which are incorporated into our various water treatment and recycling systems, and have established an energy management system throughout our fabs. Knowing exactly how much power each facility is consuming helps us work towards achieving the optimum conditions for green manufacturing. We know we have further to go and are committed to using green power to further reduce our impact on the environment.

We can expect to see more foundries spring up in the United States as part of a government drive for domestic manufacturing. Environmental sustainability must always be a key consideration when building new facilities, and we hold ourselves to stringent standards, including a process wastewater reclaim rate of more than 85% and a 350% usage rate for every drop of water.

A diagram of the water management system at one of TSMC’s sites. (Click on the image for a larger view).

The water challenges in every region and city vary. To be ready to address them, we believe we must invest consistently in technology to advance water treatment, maximize water recycling and reduce water consumption, as well as expand water sources to safeguard the environment and protect local communities. In Taiwan, our near-term plans include the construction of an off-site reclaimed water recycling plant. This will collect discharged wastewater from our treatment plant, which in turn will replenish city water. In Arizona, home of our latest fab, we are working closely with city government and ecosystem partners to ensure the same high standards for sustainable water resource management.

Water management starts with our employees. It is up to us to motivate all of them to contribute to initiatives. Setting clear goals is part of this, but it is also about fostering a culture that encourages sustainability innovation, including things like environmental protection and habitat restoration at an individual level and recognizes and rewards those efforts. We are goal-oriented and outline execution plans and results in our corporate responsibility reports annually. These targets are directly linked to personal performance assessments and financial incentives. But we also see it as important to give staff the platforms to detail their achievements. This leads to a virtuous cycle in which staff simultaneously gain recognition and inspire others to act.

Effective water management is very much a team effort, and our collective future depends on getting it right.

This article was originally published on EE Times.

Arthur Chuang is senior director, Facility Division, TSMC

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