IBM says its scientists have made a breakthrough in transistor technology that could someday enable a new class of much smaller and faster computer chips.
IBM researchers said they built the first array of transistors out of carbon nanotubes - tiny cylindrical structures of carbon atoms that are some 50,000 times thinner than the diameter of a human hair.
Researchers have already found a way to form the nanotubes into transistors 500 times smaller than today's silicon based transistors, IBM said. But only now have they found a process that may allow them to be mass produced.
"We can make good semiconductors out of carbon nanotubes," said Tom Theis, director of physical sciences for IBM research.
"What our folks have been doing is trying to figure out ways to make these better and faster so that they can continue studying the properties and developing them," he added. "Our multi-year goal here is to come to an understanding if these will be good enough to replace silicon in microelectronic devices."
IBM researchers said they've found a process by which they can form batches of nanotube transistors, which are as small as 10 atoms across. Until now, nanotubes had to be positioned one at a time or by random chance, IBM said.
The achievement was seen as a step toward eventual mass production of computer chips using the technology - making it a contender as a possible replacement for silicon.
Scientists are looking for such new materials and processes for improving computer chips, as chipmakers expect that at some point, within the next decade or two, silicon-based chips cannot be made any smaller.
Carbon nanotubes are the strongest fibre in all of nature, taking advantage of the carbon bond - which is what makes a diamond so hard. So they may eventually be used to make all kinds of ultra-light and ultra-strong materials.
IBM is studying carbon nanotubes because they are extremely good electrical conductors, Theis said, which makes them really good wires.
"The can carry higher current per unit area, more electrons through a tiny cross section of tubes, than any known conductor," he said. "Far more than you could put through copper wire, which is currently used in chips."
He added that when the tubes are rolled up into a straight structure it can form a wire, but with a twist or a kink in the structure, the nanotubes become a semiconductor.
Such a semiconductor conducts just enough electricity so you can turn it on and off by applying an electrical field. That's how a transistor works, and what is currently done with silicon chips. "You can do the same thing with a carbon nanotube," said Theis.
The breakthrough at IBM was the ability to overcome a natural tendency of the two structures - the straight structures and the twisted ones that form semiconductors - to adhere to each other. If they are stuck together, it hinders the ability to apply a current to the semiconductor to basically turn it on and off.
IBM was able to develop a process that overcame that - basically by projecting a mask onto the tubes and then turning off the semiconducting tubes - effectively insulating them from electricity.
Then researchers apply a jolt of electricity that destroys all the metallic, non-semiconducting tubes, leaving a bunch of the semiconducting tubes behind.
IBM hopes to get the technology into development, or to the point at which it considers the actual manufacture of viable products, within three years.
