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> Doesn't chip making a lot of water Can anyone share an insight on why this is the case? (I'm assuming it is true because I've heard the claim quite often on
by ckastner 5y ago
> Doesn't chip making a lot of water
Can anyone share an insight on why this is the case? (I'm assuming it is true because I've heard the claim quite often on HN.)
It's not really obvious to me where water is consumed during the fabrication process. It doesn't end up in the chips, so where does it go? If it were just used for cooling, it would be returned somewhere.
- mwint 5y agoThere’s a lot of chemistry as part of the chip making process. Water is often an ingredient mixed with concentrated nasty stuff to get less concentrated, but still nasty stuff. Then they do something with it (like wash a part), but you can’t then effectively recover all the water. This is how it was explained to me by someone who works directly on the process; I could be butchering the explanation.
- deelowe 5y agoThis is my understanding as well. There's a lot of washing of components involved in the process. Cleanliness is crucial to chip manufacturing so wafers are constantly being washed. In newer lithographies, water is a crucial part of the the photo etching process itself (X-Ray IIRC).
- sanxiyn 5y agoRe use of water in lithography: it became necessary at 90 nm level (~2004), so it is not exactly new. Water is used to bend light. (Isn't it amazing?) https://en.wikipedia.org/wiki/Immersion_lithography https://en.wikipedia.org/wiki/Immersion_lithography While this use requires extreme purity, it is not a big use in terms of volume.
- ksec 5y agoAs mentioned, they are used to clean / wash off chemicals from wafers. And not just any water, but Ultrapure Water [1], it is an actual terminology, not marketing speak. [1] https://en.wikipedia.org/wiki/Ultrapure_water https://en.wikipedia.org/wiki/Ultrapure_water