Nanotube Electronics Could Replace Silicon – IBM Research Breakthrough

The contact points for the nanotubes create a lot of electrical resistance, which hinders overall performance.

IBM says that its scientists have made a major engineering breakthrough that could help speed the transition from silicon-based transistors to those constructed from carbon nanotubes. Now, with its latest research, the company argues that it has overcome “the other major hurdle in incorporating carbon nanotubes into semiconductor devices”, according to IBM, “which could result in smaller chips with greater performance and lower power consumption”. In a Q&A posted on the IBM Research blog, Nanoscale device and technology manager Shu-Jen Han explained what still needed to be done in order to use carbon nanotube transistors in a viable processor: “We’ve developed a way for carbon nanotubes to self-assemble and bind to specialised molecules on a wafer”.

IBM has built functional silicon-germanium transistors at 7 nanometres, but say that this pushes the limits of what the can be done with the material, while Intel has stated that it won’t be using silicon beyond the 10nm scale – current Intel CPUs are at 14nm, and the next generation will be 10nm.

As part of the world’s long search for technologies that can stave off The End of Moore’s Law, and carbon nano-tech is a multi-billion dollar research effort in IBM alone. But that’s where the carbon nanotubes come in.

Using this approach, the researchers in Yorktown Heights, N.Y., demonstrated the smallest contacts for carbon nanotubes at 9 nanometers, where the performance did not suffer despite the tiny dimensions.

‘As silicon technology nears its physical limits, new materials, devices and circuit architectures must be ready to deliver the advanced technologies that will be required by the cognitive computing era’

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“We know what the issue has been, and the limits of the technology, for years”.

Big Blue has fetched out the hand-on-a-stick to give its back a pat over what it calls a “breakthrough” in carbon nanotube electronics: making a nano-scale contact whose resistance doesn’t rise as its size is squeezed.

“These chip innovations are necessary to meet the emerging demands of cloud computing, Internet of Things and Big Data systems”, said Dario Gil, vice president of science and technology at IBM Research, in a statement.

The chips are made from carbon nanotubes consist of single atomic sheets of carbon in rolled-up tubes. Inside a chip, contacts are the valves that control the flow of electrons from metal into the channels of a semiconductor.

False-colored SEM image showing a set of devices with different contact geometries fabricated on the same nanotube to verify that the contact size can shrink without reducing device performance. Known as an “end-bonded contact scheme” the 10 nm electrical leads are chemically bonded to the metal substructure.IBM’s proof-of-concept chip has nine-nanometer channels, but before the breakthrough the contacts were giant in comparison. Until now, decreasing the size of the contacts on a device caused a commensurate drop in performance – a challenge facing both silicon and carbon nanotube transistor technologies.