The research wing of IBM claimed it has made an engineering breakthrough which could mean carbon nanotubes will displace silicon transistors for future computers.
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In a release about its breakthrough, IBM said its researchers successfully shrunk transistor contacts in a way that didn’t limit the power of carbon nanotube devices.
At the same time, he acknowledged that challenges remain in perfecting carbon nanotube transistors, but he said that IBM is increasingly confident that they can be overcome.
IBM has been investing heavily in carbon nanotube research, and has already shown that carbon nanotube transistors can be used as excellent switches at channel dimensions of less than 10nm: “the equivalent to 10,000 times thinner than a strand of human hair and less than half the size of today’s leading silicon technology”, the company explained.
IBM’s new contact approach overcomes a hurdle in incorporating carbon nanotubes into semiconductor devices, which could result in smaller chips with greater performance and lower power consumption. But that’s where the carbon nanotubes come in.
“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. Using this technique, the group demonstrated that contacts less than 10 nanometers long didn’t compromise performance. “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”. “The major issue for scaling, not only for carbon nanotubes, but for silicon and III-V materials [indium, gallium, arsenide] is the contact-which is no longer scaling”. IBM’s carbon nanotube results satisfy the contact requirement all the way up to the 1.8-nanometer node (four technology generations of manufacturing technology away), showing that the technology can scale sooner than the industry thinks, IBM said.
“This is an important advance but there are many other challenges to be solved such as how to purify the nanotubes, how to place them properly, and we also made good progress there but when we are talking about new technology so many things have to be right”. Inside a chip, contacts are the valves that control the flow of electrons from metal into the channels of a semiconductor.
To overcome that the researchers, led by Qing Cao, created an “end-bonded contact scheme that leads to size-independent contact resistance”. Better transistors can offer higher speed while consume less power. “Our novel approach is to make the contact from the end of the carbon nanotube, which we show does not degrade device performance”. The existence of single-walled carbon nanotubes and their marvelous semiconductor properties occurred independently at both NEC and IBM, and Big Blue has been interested in capitalizing on that discovery for well over a decade.
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The reflection of Roland Germann, manager, Nanotechnology Center Operations at IBM Research – Zurich in the clean room.
