Updated: Silicon threatening planet – official
Costs many, many gallons for one wafer
Factual details have emerged about the high cost of producing a single eight inch wafer of silicon -- and it's bad news for the planet. According to Web site The Silicon Valley Toxics Coalition, it takes many thousands of gallons of water for any fabrication plant to produce a single eight inch wafer. It estimates nearly 3,000 gallons for one wafer, which is bad news for Irish people drinking Guinness. Worse, according to the site, there are by products which do not help human survival on the planet. All companies which make chips and have fabs are producing many tons of toxic waste, the coalition alleges. But the problem with water is one the site highlights. It seems, from what the site says, human beings have a stark choice between silicon and water. A virtual desert could be produced, it alleges. The coalition has chapter and verse on the subject, with many scientists backing it up. An Intel representative told The Register that its conscience was clear on the Guinness front. Its fab in Leixlip, near Dublin, is up-stream of the Guinness fab. "We use 1,000 gallons per wafter and 80 per cent of the water is recycled. The amount of water lost in the process is 200 gallons. "It takes four days to get the microbes out and then we have to put the microbes back in again," he said. "But the recycled water doesn't get into the Guinness." The microbes had to go back into the water because the fish in the river Liffey would die from pure water. Ding, ding ding ding ding. Guinness Inside. A senior executive at a database company quipped: "So how do they hide 200 gallons of water per wafer - surely you can't get that much into a single wafer. Or maybe they are storing it in the plant in which case it will surely burst eventually and cause a catasrtophic flood downstream at the Guinness fab. And if they are simply pumping it into the ground, then Ireland will soon simply float free and drift out into the Atlantic Ocean, until it eventually reaches Boston, which is probably where it belongs." The Toxics Coalition site does not pose the question which occurs to us, which is, is it better to be intelligent and living in a desert without water or stupid in a lush green place with plenty to drink? Homer Simpson was not available for comment at press time. ® * A reader responded to this story after it was posted with the following comments: "As someone who works on control software for the largest producer of semi-fab equipment, I've been appalled by the huge amounts of cooling water used by some fabs. There's no reason why the cooling water couldn't be sent out to a heat exchanger, and re-used. Exhaust gases on many semi-fab machines could also be cleaned up by better design." He said that simple retrofits to existing equipment could help a lot.