ReadExplain It Simply04 Oct 20261:443 min readSemiconductors: chips, fabs & yield

Every Chip Factory Keeps a Liquid That Would Hurt You. It Is Water.

A Chip Factory Makes the Cleanest Water on Earth. Nobody There Is Allowed to Drink It.

One plain, unlabelled drinking glass filled with perfectly clear water, standing alone on a clean pale grey surface in soft natural daylight. the water is flawlessly transparent and throws a single bright caustic of light on the surface beside the glass. nothing else in the frame at all: no table setting, no jug, no droplets, no background objects. enormous calm empty space around it

The picture for this piece. Made for it: no people, no brands.

In plain words

Every chip factory keeps a liquid that would hurt you if you drank it. It is water.

Ordinary tap water arrives at the factory and everything is taken out of it: minerals, specks, dissolved gases, bacteria.

Why go that far? Because one grain of salt, dried onto the disc of silicon a chip is built on, is enough to ruin it.

Water that empty is hungry. It pulls minerals out of whatever it touches, so the pipes are a special plastic, and nobody there drinks it.

The rinse time and the purity limit are part of the recipe each machine runs. The software holds a batch at the tool until both are met.

One wafer takes about 8,300 litres of water. TSMC says it keeps 161. A rival, United Microelectronics, has reported recycling above 90% at one plant.

Picture it. It is the difference between the water that passes through a mill wheel and the water the mill actually takes out of the river. One number is enormous and the other is small, and both are true.

Why it matters to you. Both numbers are published and both are true, and they support opposite arguments. If you take one thing from this, take the question: when a figure says how much something used, ask what came back.

Terms in this piece

TSMC Taiwan Semiconductor Manufacturing Company: The world's largest contract chip maker; it makes most advanced AI chips.

Mechanism diagram: Every Chip Factory Keeps a Liquid That Would Hurt You. It Is Water. — The mechanism, in one picture.Open full size

The number

18.2 MOhm-cm

THE PURITY CEILING AT 25C, ELGA 2026

The honest caveat

The two headline numbers measure different things: 8,300 litres is water passing through the process for one wafer, and 161 litres is what TSMC reports as consumed per 12-inch wafer equivalent after recovery. The gap is recycling. Nothing here argues that fabs use too much water or too little, and no company is being praised or criticised; TSMC appears because it publishes the clearest figures.

Your turn

Which number would you have quoted: the 8,300 litres that passed through one wafer, or the 161 that were kept?

Argue with me on LinkedIn

Sources

PressTSMC 2024 sustainability reporting (published 2025) [primary]: water consumption per unit product of 161.0 litres per 12-inch wafer equivalent, an 8.7% reduction versus 2023; 284.6 million cubic metres recycled through recovery systems; 5.54 million cubic metres of additional water savings - https://esg.tsmc.com/en/focus/greenManufacturing/waterResourceManagement.html link
PressPer-wafer water intensity (MKS, 2024; Semiconductor Engineering, 2024) [industry reference]: approximately 8,328 litres of water for an integrated circuit on a 300mm wafer, of which about 5,678 litres is ultrapure; cross-checked against the independently reported figure of roughly 2,200 US gallons per wafer with more than 68% ultrapure - https://www.mks.com/n/semiconductor-ultrapure-water/ - https://semiengineering.com/how-semiconductor-fabs-use-water/ link
PrimaryUltrapure water specification and behaviour (ELGA Lab Water, 2026; Membrane Solutions, 2025) [industry reference]: the 18.2 megohm-centimetre resistivity ceiling at 25 degrees C; why ultrapure water acts as an aggressive solvent and leaches ions from pipework and tissue; why it is unsuitable as drinking water - https://www.elgalabwater.com/ultrapure-water - https://www.membrane-solutions.com/blog-Can-You-Drink-Ultrapure-Water link
PressDaily fab consumption and the Arizona figures (24 August 2026, and 2026 reporting) [press]: a large fab at several million gallons per day; TSMC Arizona reported at about 4.75 million gallons per day and recycling about 65% of intake - https://ahwatukee411.com/4-75-million-gallons-a-day/ - https://www.azfamily.com/2026/08/24/arizonas-chip-footprint-grows-tsmcs-water-demand-sparks-questions/ link
AnalystRecycling rates in context (Robeco, March 2026; The Diplomat, September 2024) [analyst / press]: 2023 process water recycling of about 90% at TSMC, with UMC in the mid-80s overall and above 90% at Fab 12a; Taiwan water stress and the 2021 drought - https://www.robeco.com/en-int/insights/2026/03/why-the-future-of-chips-depends-on-water - https://thediplomat.com/2024/09/how-water-scarcity-threatens-taiwans-semiconductor-industry/ link

Read the full script (238 words)

That sounds like a riddle, and the answer is the whole story. Ordinary tap water arrives, and the factory takes everything out. Every mineral, every speck, every dissolved gas, until almost nothing is left. So why would you go that far? Because one grain of salt ruins a disc of silicon, called a wafer, and the rinse must leave nothing behind. And the catch you would never expect? Water that empty is hungry: it pulls minerals out of whatever it touches, including the pipes, and including you. It cannot sit still either: standing water pulls carbon dioxide from the air, so it runs in a loop, cleaned on the way round. How much do you think one wafer takes? About eight thousand three hundred litres, and a big factory runs two to four million gallons a day. And if the purity ever drops? Batches stop at the machines, because a step you cannot rinse properly is not allowed to start. So does all that water disappear? It does not, and this is the part you never hear. Most of it comes back. TSMC, the world's biggest chip maker, kept only one hundred and sixty one litres per wafer last year and recycled two hundred and eighty four million cubic metres. Eight thousand litres touch the wafer. One hundred and sixty one are actually spent. So which number would you have quoted? See you next week, one layer down.

Semiconductors Semiconductor Manufacturing Wafer Fab Ultrapure Water Water Stewardship Sustainability Smart Manufacturing Industry 4.0 Foundries Fab Operations

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