CIO —
Researchers at IBM have taken a large step toward creating nano-scale processors. They have built an electronic integrated circuit by combining conventional silicon technology with a carbon nanotube molecule.
The resulting hybrid circuit is still slower than a conventional component, but it is an important proof of concept, said Joerg Appenzeller, research staff member at IBM’s Thomas J. Watson Research Center in Yorktown Heights, N.Y.
IBM released the news Thursday in a paper published in the journal Science.
The research could have a large impact on the design of faster processors. Forty years after Intel cofounder Gordon Moore predicted that the number of transistors on a chip would double every two years, engineers are finding it hard to keep up with "Moore’s Law."
Industry leader Intel has announced plans to move from 65-nanometer chip geometry to a 45-nanometer plan by 2007. But many engineers warn that chips cannot get much denser without running into problems like overheating. A hybrid processor would avoid that problem because electrons flow through nanotubes at high speed and low friction.
Analysts said IBM’s achievement was an important step toward reaching the goal. "Given that they’re looking at a 10-to-15-year time horizon until this can become a game-changer in the industry, there is a tremendous amount they have accomplished," said Vahe Mamikunian, an analyst with Lux Research, New York City.
Many researchers have noticed the great physical attributes of carbon nanotubes before, such as offering higher speed, lower power consumption and higher densities, he said.
One company—Nantero, in Woburn, Mass.—is using nanotubes to create high-density nonvolatile memory. Other scientists are using the thermal conduction properties of nanotubes to draw heat away from processors. That work is happening at Fujitsu, in Tokyo, Japan, and NanoConduction, in Sunnyvale, Calif.
"IBM’s work is different, because no one has really looked at using carbon nanotubes as a replacement for silicon," Mamikunian said. "Now they have to scale that up to gigahertz and terahertz levels. They haven’t found a switching speed limit yet, so theoretically it shouldn’t be a problem."
A nanotube is like a straw built of carbon atoms, frozen in a form between a crystal and a molecule. That allows it to be very small, 50,000 times thinner than a human hair. The IBM team took a carbon nanotube and attached standard wires to it, sticking out like the teeth of a comb. That allowed the team to use a single molecule as the base for all components in the circuit, using standard semiconductor processes.
