Big Blue Goes Green, Recycling Silicon

IBM announced Tuesday 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 in order 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 theirs 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 leaving them in better condition for reuse. The entire process to clean an 8-inch wafer is about one minute. Eric White, the inventor of the process, said that 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, Vermont, has been using the process and reported an annual savings in 2006 of more than US$500,000 dollars. Expansion of the new technique has begun at IBM's site in East Fishkill, New York, and 2007 savings estimates are more than $1.5 million. The Vermont and New York plants are IBM's only semiconductor manufacturing sites.

Chris Voce, an analyst with Forrester Resarch, does not 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 for the semiconductor manufacturing industry.