IBM Makes Carbon Nanotube Breakthrough

IBM Research announced an invention that paves the way for a post-silicon future with carbon nanotube chips.

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IBM Research announced a major engineering breakthrough that could accelerate carbon nanotubes, replacing silicon transistors to power future computing technologies.

IBM scientists demonstrated a new way to shrink transistor contacts without reducing performance of carbon nanotube devices, opening a pathway to dramatically faster, smaller and more powerful computer chips beyond the capabilities of traditional semiconductors. The results will be reported in the October 2 issue of Science magazine.

In an interview with eWEEK, Shu-Jen Han, manager of the Nanoscale Science & Technology Group at IBM Research, said IBM's breakthrough overcomes a major hurdle that silicon and any semiconductor transistor technologies face when scaling down.

In any transistor, two things scale: the channel and its two contacts. “When we talk about the transistor scaling there are two parts,” Han said. “Most people focus on the transistor channel length -- channel length scaling. But when you look at a transistor there is the channel but also contacts. Our breakthrough is on the contacts.”

As devices become smaller, increased contact resistance for carbon nanotubes has hindered performance gains until now. These results could overcome contact resistance challenges all the way to the 1.8 nanometer node – four technology generations away.

Carbon nanotube chips could greatly improve the capabilities of high performance computers, enabling faster analysis of big data, increased power and battery life of mobile devices and the Internet of things, and allowing cloud data centers to deliver services more efficiently and economically.

IBM’s breakthrough will help enable “anything related to computation – from high performance computing to lower power computation like mobile phones,” Han said. “Our goal is to try to push carbon nanotube technology beyond silicon, so there are many challenges that we have to solve and one of the biggest ones is the contacts. We tackled that with this work. But our ultimate goal is to try to replace silicon and continue to push Moore’s Law.”

Han added that IBM’s breakthrough brings the company a step closer to the goal of a carbon nanotube technology within the decade.

Silicon transistors, tiny switches that carry information on a chip, have been made smaller year after year, but they are approaching a point of physical limitation. With Moore's Law running out of steam, shrinking the size of the transistor – including the channels and contacts – without compromising performance has been a vexing challenge troubling researchers for decades.

IBM has previously shown that carbon nanotube transistors can operate as effective switches at channel dimensions of less than ten nanometers – 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. IBM's new contact approach overcomes the other major hurdle in incorporating carbon nanotubes into semiconductor devices, which could result in smaller chips with greater performance and lower power consumption.