The development of ever-thinner wires on chips looks to be the forecast after the chipmaker's association yesterday laid out its 'roadmap' for the next 15 years.

The SIA (Semiconductor Industry Association) released the 2001 edition of its International Technology Roadmap for Semiconductors yesterday, calling for a more aggressive push to smaller circuit sizes than previously planned.

Though the majority of today's PCs use processors with a circuit size of either 180 nanometres (0.18 microns) or 130 nanometres (0.13 microns) , the new roadmap shows the industry planning to deliver 90-nanometre circuits by 2004, and 22-nanometre circuits by 2016, the SIA said.

To put that into perspective, the width of a human hair is about 100,000 nanometres thick. Shrinking the size of circuits has been largely responsible for the dramatic improvements in chip performance over the past decade as well as power and heat reductions.

These new figures surpass the organisation's previous roadmap, released in 1999, which called for 100-nanometre circuits by 2005, shrinking to 35 nanometres by 2014.

As circuits shrink, the performance of chips can be increased without greatly increasing power consumption or the amount of heat generated. Companies can also get more chips from each silicon wafer by using a smaller process, which helps them keep prices lower. Intel said earlier this year that the 0.13-micron manufacturing process allows it to cut approximately twice as many chips as the 0.18-micron process from a wafer of the same size.

The ITRS roadmap looks 15 years into the future, and provides the industry with guidance about what to plan for in the future. It's arrived at by consulting 800 semiconductor experts from around the world, the SIA said.

"In the past, this has been a major synchronisation method for the industry," said Nathan Brookwood, principal analyst with consultancy Insight 64 in Saratoga, California. "You can do things that aren't on that roadmap, for sure, but you would be swimming against the tide."