Second life for old chips

Big Blue makes breakthrough on recycling semiconductors
IT giant IBM has a new technique for cleaning data off wafer disks, and it’s secure enough that the wafers can be sent back to work – taking some of the pressure off silicon supplies in computing and the fast-growing solar sector.

Made from silicon, about 250,000 wafer disks are produced every day worldwide. They wind up in everything from computer processors and iPods to fridges and cars.

Around three million used disks are scrapped each year. Because they contain intellectual property, these are usually either crushed or burned (at very high temperatures), and the residue sent to landfill. It’s both energy-intensive, and incredibly wasteful.

Using a new, efficient pattern removal technique – involving water and abrasive pads – the disks can now be cleaned and reused, either for computing, or to make the photovoltaic cells of solar panels. As well as saving IBM money (about $1.5 million in 2007), it saves solar manufacturers 90% of the energy it would take to make the cells from scratch. It should also help address the present silicon shortage which is threatening to stymie the growth of the solar sector – currently running at around 30% per year.
– David Howells

7 January 2008

David Howells