Nanotech to turbocharge PC and mobile data

Scientists have demonstrated for the first time that carbon nanotubes can route electrical signals on a computer chip faster than traditional copper or aluminium wires at speeds of up to 10GHz.

The University of California Irvine scientists in The Henry Samueli School of Engineering said that the breakthrough could lead to faster and more efficient computers, and improved wireless network and cellular phone systems.

"Our prior research showed that nanotube transistors can operate at extremely high frequencies, but the connections between the transistors were made out of somewhat slower copper, thus forming a bottleneck for the electrical signals," said Peter Burke, assistant professor of electrical engineering and computer science at UC Irvine.

"In this technology we show that nanotubes can also quickly route electronic signals from one transistor to another, thus removing the bottleneck."

The researchers explained that electrical signals are routed at high speed through virtually all modern electronic systems and through the airwaves in all modern wireless systems.

"From now on, any time a nanotube device is used anywhere in the world in a high-speed electronic device, computer, wireless network or telephone system, people will benefit from this technology," added Burke.

A nanotube is commonly made from carbon and consists of a graphite sheet seamlessly wrapped into a cylinder only a few nanometres wide. A nanometre is one billionth of a metre, about the size of 10 atoms strung together.

Most of the layers in a modern semiconductor chip are dedicated to interconnect wiring, making the material used, and its speed, extremely important.

The semiconductor industry recently shifted from using aluminium to copper as interconnects because copper carries electrical signals faster than aluminium.

Burke explained that, based on the latest experiments, changing the industry from copper to nanotubes would provide an even larger performance advantage in terms of speed.

Before such a shift could occur, however, nanotube technology would need to be economical to manufacture, and require precise assembly, which scientists are currently working on.

Having developed both high-speed nanotube interconnect technology and high-speed nanotube transistor technology, the UC Irvine researchers hope to integrate the two into an ultra-high-speed all-nanotube electronic circuit, faster than any existing semiconductor technology.

The Army Research Office, the Office of Naval Research, the Defense Advanced Research Projects Agency and the National Science Foundation provided funding for the research, which took place at UC Irvine's Integrated Nanosystems Research Facility in The Henry Samueli School of Engineering.