IBM has revealed it is able to boost chip speeds by up to 35 per cent – by stretching the silicon, the material at the heart of microchips.

Dubbed "strained silicon", the technology stretches the material, allowing electrons to move faster through the chip's transistors, increasing performance. The technique also gives the option of trading off performance against savings of about a third in power consumption, IBM said.

To stretch the silicon, IBM deposited silicon atoms on a substrate that has atoms spaced further apart than the natural spacing of silicon atoms. The silicon atoms then automatically line up with the atoms in the substrate, according to IBM. The company expects the technique to be commercially available by 2003.

Power play IBM spokesman Rupert Deighton, said:
"Electrons are the ones and zeros running through the chip and they can flow up to 70 per cent faster in stretched silicon, resulting in 35 per cent faster performance, and an equivalent reduction in power consumption for a chip made using this material."

He added: "Imagine strained silicon as a tarmac road and currently used silicon as a hedge. A tarmac road will offer less resistance than a hedge, allowing you to run faster."

Although strained silicon can be used for any kind of silicon-based chip, Deighton said he expects the stretched material to show first in high-performance chips.

"The object is high performance. Networking chips and application-specific integrated circuits (ASICs) would be the first in line," he said, noting that strained silicon could also be used in any battery powered device, such as wireless handheld devices.

Another recent improvement in chip performance is scaling – a process by which chip transistors are made smaller and packed closer together.

Improving chip performance by scaling is expensive, as it requires chipmakers to buy new manufacturing hardware with each change in scale.

"Reducing the actual size of the transistors on a chip requires refined and redefined lithography. One plant costs billions of dollars. With our new process we don't have to shrink to get incremental performance," said Deighton.

Stretching silicon is not an IBM invention, Deighton acknowledged.

"We took the theoretical concept and put it into practice, and can now take it into production on high-volume, cost-effective production lines," he said.