IBM goes for mini microchips

A NEW generation of even smaller, even faster microchips will soon be incorporated into consumer items after years of development by the computer giant IBM.

The result could be smaller mobile phones and hand held computers able to perform more functions for longer on existing battery technologies.

But a British expert who has watched the development of the new technology over the past 30 years warned yesterday that chip companies will be reluctant to give up their multi-billion pound investments worldwide in chip plants to make old silicon wafers.

"It's like fusion power," said Peter Hemment, professor of semiconductor technology at Surrey University. "For decades that has been 30 years in the future, and it still is. This technology has been proven since the 1970s, and people have known they would have to switch to it. But they haven't, so far."

That position may be about to change radically. IBM said yesterday that it will start producing high volumes of processor chips using the new technology, called "silicon on insulator" (SOI), from next year.

The key to the breakthrough is a still-secret means of mass-producing SOI chips, which had previously only been made in limited volumes.

Among the first to benefit should be Apple Computer, for which IBM produces the PowerPC processor. That will be among the chips using SOI technology, which produces chips one-third smaller than the silicon wafer, and which can speed a chip up by at least 25 per cent without any other design changes.

SOI differs from existing chip designs by putting the millions of transistors that make up a processor on to an insulating surface instead of a semiconductive layer. Current thus flows more freely, reducing heating effects, and there is less interference between the transistors, separated by only thousandths of a millimetre.

The SOI chips can also be made radiation-proof - which led to their early adoption during the Cold War by the military, worried about the effects of a nuclear strike. One-off SOI chips are also used in satellites, which are exposed to harsh solar radiation.

Though it is easier to make circuits with the existing silicon fabrication method, the finished chip then requires higher currents to work properly and has a lower limit on size before bizarre quantum effects take over. SOI avoids those problems because of the insulating layer below the current- carrying silicon.

Global uncertainty in the chip market could put manufacturers off investing billions to set up SOI fabrication lines.