Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: Kosh on March 05, 2009, 06:23:00 am
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After reading about the closing of MOS's 70's era fabrication plant in 2001 by the EPA, I was wondering what pollution is a result of making semiconductors? How is it now compared with back then?
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They use toxic stuff to make them, so disposal is probably an issue. The 70s era version was probably too outdated to meet modern regulations. Kinda like the CO2 emissions regulations of cars in China compared to in the West.
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Perhaps it's due to the fact that from the 80's onwards, the metal part of MOS is kind of a lie, since MOS aren't made of metal anymore, and so, perhaps the previous process was more pollutant than the current one.
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This is a list of what this manufacturer doesn't use.
http://www.fairchildsemi.com/company/green/substances.html (http://www.fairchildsemi.com/company/green/substances.html)
Polychlorinated biphenyls (PCBs) were often used in transformers and capacitors but they've been phased out nowadays (I think) due to their persistence in the environment and toxicity.
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The pollution isn't so bad. The clincher is the fact that semiconductors are made out of children's bones.
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The pollution isn't so bad. The clincher is the fact that semiconductors are made out of children's bones.
So that's why the fundies say modern technology was made by satan........
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Thought I might throw in some info (and this applies to photovoltaics as well)
Semiconductors (at least, the common, garden variety) are all made from silicon. In order to modify the electron levels in the silicon (i.e. to create donor or acceptor atoms) you gotta add 'dopants' like phosphorus, boron, arsenic and a few other nasties. These are all mixed in during production of the ingot, before sawing it into wafers.
The transistors in your mobile phone that do the transmission component are probably Gallium Arsenide (GaAs), again, nasty stuff.
The actual production process involves a number of steps, depending on the technology and process, usually involves a number of steps including a number of lithographic steps (using a UV photoresist - pretty nasty stuff), metal deposition and etching (sometimes HF is used for an etch step as it attacks silicon dioxide, but not silicon).
HF is a real nasty one since it is a weak acid by definition, and it goes straight through the skin to eat at the calcium in your bones (and you don't know it at the time, and die a horrible, painful death a little while later).
So there ya have it (what I can remember - it is late at night here!) of silicon. Most of the waste is VERY carefully controlled because of how toxic and dangerous it is.
I can dig up my notes, and I'm sure I'll find a few more!
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the worst form of pollution is humans. im not concerned about toxic stuff.