IBM to recycle silicon for solar

IDG News Service - IBM announced today that it has created a process allowing its manufacturing facilities to repurpose otherwise scrap semiconductor wafers.

Since the silicon wafers need to be nearly flawless to be used in computers, mobile phones, video games and other consumer electronics, the imperfect ones are normally erased with acidic chemicals and discarded. IBM had been sandblasting its flawed wafers to remove proprietary material. Some of the pieces, called "monitors," are reused for test purposes.

The new process cleans the silicon pieces with water and an abrasive pad, which leaves them in better condition for reuse. The entire process to clean an 8-in. wafer is about one minute. Eric White, the inventor of the process, said IBM can now get five or six monitor wafers out of one that would have been crushed and discarded. The cleaned wafers can also be sold to the solar-cell industry, which has a high demand for the silicon material to use in solar panels. White said that shortage would need to be "extreme" to use the wafers in consumer electronics, and that IBM does not plan to do so.

The IBM site in Burlington, Vt., has been using the process and reported an annual savings in 2006 of more than $500,000. Expansion of the technique has begun at IBM's site in East Fishkill, N.Y., and the company estimates its 2007 savings are more than $1.5 million. The Vermont and New York plants are IBM's only semiconductor manufacturing sites.

Chris Voce, an analyst at Forrester Resarch Inc., said he doesn't anticipate savings for the end user, but added, "When a semiconductor company can improve its process and drive efficiency into their manufacturing process, that's always great for their margins, but it's even better when there are broader benefits for the environment." Annually, IBM estimates that the semiconductor industry discards as many as 3 million wafers worldwide.

IBM plans to patent the new process and provide details to the semiconductor manufacturing industry.

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