IBM packs 10,000 carbon nanotube transistors onto single chip

IBM packs 10,000 carbon nanotube transistors onto single chip

Summary: Carbon nanotubes may take over from silicon as processors get smaller and more energy-efficient, and IBM has just announced a fresh breakthrough in making the technology viable.


IBM's researchers have made another breakthrough in their development of carbon nanotube technology, packing more than 10,000 working transistors made of the substance onto a single chip.

It is now a decade since IBM first announced a process for fabricating carbon nanotubes in a way that could make them usable for processors. Although silicon has allowed the industry to keep making transistors smaller and smaller, it does not work properly at the nanoscale. Another substance will have to take over for the really tiny processors of the future.

Such processors will be needed to make computing devices and sensors smaller and more energy-efficient.

Ultimately, more than a billion transistors based on carbon nanotubes will need to fit onto one chip, if the substance is to prove its worth. However, IBM's latest breakthrough marks a significant step — previously, no-one had got more than a few hundred of the transistors onto one chip at a time.

"Carbon nanotubes, borne out of chemistry, have largely been laboratory curiosities as far as microelectronic applications are concerned. We are attempting the first steps towards a technology by fabricating carbon nanotube transistors within a conventional wafer fabrication infrastructure," IBM Research physical sciences chief Supratik Guha said in a statement on Sunday.

"The motivation to work on carbon nanotube transistors is that at extremely small nanoscale dimensions, they outperform transistors made from any other material. However, there are challenges to address such as ultra-high purity of the carbon nanotubes and deliberate placement at the nanoscale. We have been making significant strides in both."

IBM's last big breakthrough in the field of carbon nanotubes came just under a year ago, when the firm said it had managed to make a well-performing carbon nanotube transistor with sub-10nm channel lengths — this is the sort of scale where silicon is no longer viable.

Carbon nanotubes are, as their name suggests, atom-thick sheets of carbon rolled into tubes. Graphene, another nanoscale carbon substance, is also in the running for taking over from silicon, as is the graphene-like two-dimensional form of molybdenum disulphide.

Topics: Processors, Emerging Tech, IBM

David Meyer

About David Meyer

David Meyer is a freelance technology journalist. He fell into journalism when he realised his musical career wouldn't pay the bills. David's main focus is on communications, as well as internet technologies, regulation and mobile devices.

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.


Log in or register to join the discussion
  • Timely

    Carbon sequestration becomes part of electronic device production. Much better than playing around with Geo-engineering.

    Go IBM!
    Rabid Howler Monkey
    • Yes indeed

      And most importantly, as these new carbon storage devices shrink, they can fit more carbon into less space. It seems strange to think that in only a few short years we may actually run out of carbon to build them with...

      Seriously, did you read the article?
      • Or, we could mine pure limestone deposits for carbon

        And continue to belch CO2 into the atmosphere ...

        Seriously, every new use for carbon is a good thing.
        Rabid Howler Monkey
        • Alright, I'll humour you.

          Sequestering carbon is a Good Thing.

          Trouble is, the miniscule amounts they'll be using will be offset a few times by the processes used to manufacture and distribute the devices... There will be no difference to current silicon technology in that respect.

          Nanotubes use molecular amounts of carbon - you can actually count the atoms visually in a single one under high enough magnification; the hole down the middle is big enough to allow single electrons to travel down it.

          Compared to current wafer technology where the smallest wire is hundreds of times that width, and signals use many thousands or more electrons - the focus is on using less resources and less room to provide more power in the same sized device.

          Never mind feverishly squeezing the last drop of fossil fuel from every last porous rock, and melting the millions of tons of clathrates (methane, 20 times worse than CO2 as a greenhouse gas) trapped in ice.
          Never mind developing an efficient cellulose-to-ethanol process so we can carry on burning sh*t long after all THAT has gone.
          And dammit, we do carry right on breathing as well.


          • Converting sand to silicon chips

            Step one is converting sand to silicon (with impurities):

            sand + carbon + energy -> silicon (with impurities) + carbon dioxide
            SiO2 (with impurities) + C + energy -> Si (with impurities) + CO2 (ugh!)


            Thus, the production of silicon chips requires not only the mining, transportation and processing of sand (or sandstone), but also the conversion of sand into silica. Oxygen and more energy are use to remove impurities from the silica. Fossil fuels are used in the mining, transporting and processing the sand as well as for powering the electric arc furnace (i.e., energy) and heating the silica to remove the impurities. [Alternatively, nuclear fuel might be used for powering the electric arc furnace (see Palo Verde in Arizona). In this case, the exploration, mining, transportation and processing of uranium ore requires the use of fossil fuels. Not to mention creating the fuel rods for the reactor (those centrifuges and whatnot). Oh, and, what, exactly, will you do with the spent fuel rods?]

            Why not just use the Carbon (C) to produce carbon nanontubes?
            Rabid Howler Monkey
          • Oh I give up

            The moderation on this site makes it impossible to have a decent conversation. Idiots.