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Graphene Transistors 10x Faster Than Silicon

Posted by kdawson on from the can't-be-too-rich-either dept.

Asadullah Ahmad writes "IBM has created transistors made from carbon atoms, which operate at 100 gigahertz, while using a manufacturing process that is compatible with current semiconductor fabrication. With silicon close to its physical limits, graphene seems like a viable replacement until quantum computing gets to desktop. Quoting: 'Researchers have previously made graphene transistors using laborious mechanical methods, for example by flaking off sheets of graphene from graphite; the fastest transistors made this way have reached speeds of up to 26 gigahertz. Transistors made using similar methods have not equaled these speeds.'" The other day we discussed what sounds like similar research by a group of scientists at Tohoku University; that team did not produce transistors, however.

36 of 170 comments (clear)

  1. Didn't Produce Transistors? Oh Come On! by eldavojohn · · Score: 4, Informative

    The other day we discussed what sounds like similar research by a group of scientists at Tohoku University; that team did not produce transistors, however.

    Surely that is some sort of joke. From the summary of the Tokyo University article:

    A new paper entitled Epitaxial Graphene on Silicon toward Graphene-Silicon Fusion Electronics published by a group of physicists at Tohoku University in Japan has demonstrated that they can grow graphene on a silicon substrate and pair that technique with conventional lithography to create a graphene-on-silicon field effect transistor.

    Not to mention that article is a myriad of highly moderated comments admonishing the staleness of graphene on silicon transistors.

    --
    My work here is dung.
    1. Re:Didn't Produce Transistors? Oh Come On! by ground.zero.612 · · Score: 2, Informative

      The other day we discussed what sounds like similar research by a group of scientists at Tohoku University; that team did not produce transistors, however.

      Surely that is some sort of joke. From the summary of the Tokyo University article:

      A new paper entitled Epitaxial Graphene on Silicon toward Graphene-Silicon Fusion Electronics published by a group of physicists at Tohoku University in Japan has demonstrated that they can grow graphene on a silicon substrate and pair that technique with conventional lithography to create a graphene-on-silicon field effect transistor.

      Not to mention that article is a myriad of highly moderated comments admonishing the staleness of graphene on silicon transistors.

      From reading what you quoted, it's not certain that Tohoku produced anything, at least not a graphene transistor. They did however demonstrate that they can grow graphene on a silicon substrate, and that they can pair that technique with conventional lithography to create a graphene-on-silicon field effect transistor. It's just not clear that they did create a graphene transistor, or at least anything comparable to what IBM apparently is producing.

      --
      "Be prepared, son. That's my motto. Be prepared." --Joe Hallenbeck
    2. Re:Didn't Produce Transistors? Oh Come On! by VitaminB52 · · Score: 2, Informative

      Maybe you would like to read http://en.wikipedia.org/wiki/FET

    3. Re:Didn't Produce Transistors? Oh Come On! by John+Hasler · · Score: 4, Informative

      Note that the Tohoku group grew graphene on silicon while IBM produced graphene transistors on silicon carbide. These are complementary efforts, not competing ones.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
    4. Re:Didn't Produce Transistors? Oh Come On! by DJRumpy · · Score: 4, Insightful

      But there is a limit, no mistake about it. Look at modems. They went through this same limit/new limit methodology for years before they were replaced outright. I think this definitely puts silicon in it's death throws, but I expect some last minute breakthroughs that will push it a bit farther than previously though possible. This is a good thing, in that it forces us to optimize current technologies in ways that we didn't previously consider (like compression did for modems) that in turn was applied to all sorts of communication technologies, and arguably to other technologies outside of communications.

      I just see this as a necessary step before pushing off into the next big thing.

    5. Re:Didn't Produce Transistors? Oh Come On! by ElectricTurtle · · Score: 2, Interesting

      Modems are a terrible example. 56k was a ceiling codified in law by the FCC not a limit inherent to the technology. Granted using audio to transmit data would not have gone much farther, and infrastructure changes would have been necessary to make higher speeds possible while mitigating the effects of crosstalk, but the FCC regulation was just a lazy way of brushing that aside. When broadband options overtook dial-up, the issue was moot.

      Hard drives would be a more interesting example. There is an industry that keeps changing the maximum, from new perpendicular storage now to using heating lasers to increase data density. Barriers keep getting broken on what is essentially the same old media. However once the slow speeds of holographic storage are solved, there is no doubt that 3D storage will overtake magnetic-based media. These sorts of sea changes are brought about by thresholds. Until these concepts graduate from prototype to production AND cost so ridiculously less per ghz than existing tech, it'll be silicon for the foreseeable future.

      --
      I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
    6. Re:Didn't Produce Transistors? Oh Come On! by wurp · · Score: 4, Informative

      I think you're just too young to have seen the whole chain of "limits" on modem speeds. For a long time we were told that 9600 baud was the absolute maximum speed, limited by the fundamental physics of modem technology over phone wire.

      See http://en.wikipedia.org/wiki/Modem#Breaking_the_9.6k_barrier

    7. Re:Didn't Produce Transistors? Oh Come On! by DJRumpy · · Score: 2, Interesting

      I never mentioned the 56k limit. I'm referring to the fact that the same signal is used but tweaked each generation to allow greater speeds in ways that weren't even considered. For instance, from 300 baud modems to 56K modems. Frequency shifts, phase shifting, duplexing, echo cancellation, QAM, etc. All of these pieces allowed more data to be sent over the same old twisted pair in ways they never thought possible.

      All of those advances were evolutionary rather than revolutionary, and they benefited all sorts of communication mediums in use today. Had we just stumbled on the next big thing without taking that path, we would have lost the benefits of struggling at the limits of that particular technology.

    8. Re:Didn't Produce Transistors? Oh Come On! by wurp · · Score: 4, Insightful

      Again, that's very easy to say in retrospect. I believe this is an almost identical situation: we have a very complex set of interactions from which we derive one number: "transistor switch speed". We believe we understand those relations well enough that we can derive a fastest speed any possible silicon design can give.

      This speed is far more similar to the "maximum" modem speed than it is to the melting point of some substance.

      Before Ungerboeck's work, information theory seemed very clear about the fastest possible rate at which data could be reliably sent on the frequencies that would "stay on the wire" without bandwidth bleedover. Ungerboeck just demonstrated that there were artificial assumptions underlying the information coding theory on which that speed was based.

      You're looking at documentation after-the-fact on modem speeds, which rightly enough talks about revolutions in theory. From the point of view of people before the revolution in the theory, you talk about physical limits. All limits we calculate are by definition theoretical limits, though.

      To paraphrase Arthur C. Clarke: When a scientist or engineer states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.

    9. Re:Didn't Produce Transistors? Oh Come On! by robathome · · Score: 5, Informative

      I think you're just misunderstanding the problem.

      The "baud rate" of telephone lines is pretty slow. Baud rate is the number of symbol transitions per second the media can support. Baud rate and bits/second have not been equivalent since Bell103a/V.21 frequency-shift-keyed modems, where 300 baud meant 300 bps, each state transition being a discrete tone that indicated a "mark" or "space" (0/1). From then on, Bell 212a/V.22 used phase-shift keying to get 1200 bps out of a 600 BAUD symbol rate, encoding two bits of information per symbol.

      POTS lines are pretty pokey - the practical maximum BAUD rate is less than 3500 symbols/sec. Where speed advancements were made in later evolutions of POTS modems were in the number of bits that could be encoded per symbol, using QAM and Trellis Modulation. A 33.6 kbps modem is encoding 10 bits per symbol onto a 3429 baud carrier.

      So, when you kept hearing "phone lines max out at less than 4800 baud", that was correct. The engineers kept wringing higher bit rates out of narrow-band POTS by putting more information on each of the symbols transmitted.

      Then, with V.70 and V.90, the modulation schemes took advantage of certain characteristics of non-muxed POTS lines to use PCM digital encoding instead of an analog audio carrier. Unfortunately, if you were serviced through a SLC-96 ("Slick") muxed subscriber loop, which multiplexed the signal from your subscriber line to the central office, you could only connect with older analog modulation schemes such as v.32/v.32bis/v.34.

      --

      At 3 A.M. you can see people's auras; at five you can see their contrails...
    10. Re:Didn't Produce Transistors? Oh Come On! by robathome · · Score: 2, Informative

      The link you provide speaks to the problems of bit-packing on the symbol states, and the solution of Trellis Modulation, which I mentioned. Trellis coding allowed for packing more than 4 bits to each symbol without increasing the error rate, leading to the development of the v.32bis standard and 14.4Kbps modems. Which is what I said - it wasn't high baud rates, but better bit packing that realized faster speeds.

      And you're still saying "baud" when you mean "bits per second".

      --

      At 3 A.M. you can see people's auras; at five you can see their contrails...
    11. Re:Didn't Produce Transistors? Oh Come On! by phantomfive · · Score: 3, Insightful

      Wow, way to close your eyes to new knowledge and ideas. That guy had something extremely insightful to say, and you missed it for the sake of an argument (and what a waste of an argument! That processor speed was a stupid thing to chase? Did you never use a Commodore 64? Sigh).

      --
      Qxe4
    12. Re:Didn't Produce Transistors? Oh Come On! by imgod2u · · Score: 2, Informative

      [quote]Again, that's very easy to say in retrospect. I believe this is an almost identical situation: we have a very complex set of interactions from which we derive one number: "transistor switch speed". We believe we understand those relations well enough that we can derive a fastest speed any possible silicon design can give.[/quote]

      No. We know the fastest speed of a MOSFET made with current fabrication technologies. The problem is that MOSFET (specifically CMOS topologies) has very very good characteristics that we like and the fabrication infrastructure (and tooling industry) exists amortizing the cost. There are many many other circuit topologies and manufacturing methods (silicon germanium, GaAs, etc.) that produce faster transistors. But moving to those are 1. expensive and 2. comes with their own limitations.

      Graphene isn't perfect either. Aside from the difficulties in fabricating it, there's also the problem that unlike MOS, there's isn't a way (yet) to make a good graphene PFET. CMOS circuits are the way they are today because using a PFET-NFET topology works really really well for digital circuits.

      Graphene (and carbon nanotubes) also have the problem that they don't really have an "off" state. There's less conductive and more conductive. CMOS at small geometries may leak current but nothing like CNT's and Graphene do. The circuits made from them are very power hungry (at least with current circuit topologies).

      There's a lot of research trying to come up with better circuits to utilize the incredible on-current states without tunneling power between VDD and GND during the "off" state.

      Before Ungerboeck's work, information theory seemed very clear about the fastest possible rate at which data could be reliably sent on the frequencies that would "stay on the wire" without bandwidth bleedover. Ungerboeck just demonstrated that there were artificial assumptions underlying the information coding theory on which that speed was based.

      Shannon Theory very well laid out the maximum data rate that could be transmitted over a medium and Trellis Modulation did not exceed that. The fundamental limits were well known and not wrong. Implementations that existed then simply couldn't come close.

  2. Commercially Viable by LikwidCirkel · · Score: 5, Insightful

    With all the stories of highly-experimental new, novel types of transistors - the majority of which are expensive-research only with no chance of commercialization any time soon, it's refreshing to see something that actually takes production feasibility into account.

  3. My prediction by Thanshin · · Score: 5, Funny

    Year 2173:

    "Hidrogen-Unobtanium polycomposites seems like a viable replacement until quantum computing gets to desktop."

    1. Re:My prediction by ground.zero.612 · · Score: 3, Funny

      Year 2173:

      "Hidrogen-Unobtanium polycomposites seems like a viable replacement until quantum computing gets to desktop."

      I came here from the year 2242 to tell you that you're wrong.

      --
      "Be prepared, son. That's my motto. Be prepared." --Joe Hallenbeck
    2. Re:My prediction by ianare · · Score: 2, Funny

      ... and all we need to do get some is to get some stupid natives out of their tree house.

    3. Re:My prediction by electrosoccertux · · Score: 2, Funny

      can you tell me when 6 digit /. UIDs will become popular?

  4. How long until you can buy it? by Cytotoxic · · Score: 3, Funny
    IBM research is typically the traditional 10 years away - but not this one... from TFA:

    "This is not pie-in-the-sky stuff, this is real," he says. "This development is really going to turn into a communications device not too long from now."

    So, I won't be playing Crysis on this transistor next month, but I might be using it to make a phone call "not too long from now".

    1. Re:How long until you can buy it? by chrysrobyn · · Score: 3, Interesting

      IBM research is typically the traditional 10 years away - but not this one

      My VLSI professor was in the forefront of the industry. He had some very good contract with some good R&D firms. One day, he told us that copper might one day replace aluminum as wires in chips. The lower resistance would make a big difference, but nobody had overcome the increased reactance yet. The next day, IBM announced that they had figured it all out. A year later, copper interconnect was being used in chips, and 6 months later, in iBooks. The same professor in a subsequent class was discussing SOI with similar promises of improvements, and similar "nobody has it figured out yet". A few weeks later, IBM came through again with an announcement. 2 years later, there it was in products.

      With game changers like SOI and copper, IBM has gone to market in much less than 5 years.

      As a former circuit designer, and still a CPU engineer, I can say without hesitation that I don't care about graphene. The transistors aren't the big factor anymore. Sure, smaller transistors are good to increase transistors per die, and reduce the distance between them, but wire RC delay is the big deal. Even if the Ioff goes down and Ion goes up, the speed of the chip isn't going to change much.

      Things aren't going to get much better than copper -- it's very good already. Even if they upgraded to slightly lower resistance silver (and talk about a reactive metal!), the delay wouldn't change much. Lower K dielectric would help too. There are some minor improvements that can be done, but we're probably talking 5% here and there, and they probably don't add up to 20%.

      Architecture changes are going to be important, from instruction optimization to multiple cores. The automated synthesis tools available also have an amazing amount of potential improvement -- placement and routing is a field with a lot of graph theory headroom. There is a world of difference still between "good enough" synthesis and what can be done by a well trained technician.

  5. Just remember. by AltGrendel · · Score: 4, Informative

    The first patent for transistors was filed in 1925.
    Look where they are now.

    --
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    - Douglas Adams

    1. Re:Just remember. by Hurricane78 · · Score: 2, Insightful

      You are forgetting the exponentinal acceleration of progress.

      So the duration between 1925 and when they were first used, is not linearly comparable to the duration between now and when those graphene ones will be first used.

      --
      Any sufficiently advanced intelligence is indistinguishable from stupidity.
  6. 3D chips by BlueParrot · · Score: 4, Interesting

    To be honest I'm more interested in seeing proper 3D chips become reality. If you find some affordable way to produce chips with, say 10 000 layers, then processing power per volume unit would increase rapidly.

    I think the major obstacle is going to be what to do about heat. The center of such a chip-stack would probably get quite hot so you probably want to run some form of liquid cooling through the chip itself. Alternatively materials like silicon carbide or diamond might be able to cope better with the high power density.

    1. Re:3D chips by damburger · · Score: 2, Interesting

      3D chip manufacturing would be interesting. As well as having a possible stepping stone towards universal fabrication, you would also have a great increase in the potential number of connections between processing elements. Connectivity is one of the main divides between silicon and neural tissue, so this may have implications for artificial intelligence. Two singularities for the price of one!

      --
      If we can put a man on the moon, why can't we shoot people for Apollo-related non-sequiturs?
  7. Sounds cheap by marciot · · Score: 3, Funny

    It was bad enough when computers were made out of mere sand, now they will be made out of coal?

    Can't they make computers out of sapphires or something so I can feel sophisticated when I buy it?

    1. Re:Sounds cheap by derGoldstein · · Score: 2, Funny

      Think of it this way: They'll be carbon-based, like us!

      --
      Entomologically speaking, the spider is not a bug, it's a feature.
  8. Bad / Incorrect Article by Anonymous Coward · · Score: 3, Insightful

    "The prototype devices, made from atom-thick sheets of carbon, operate at 100 gigahertz"

    Define operate? This sounds like the cut-off frequency, which is 100s of GHz for Si CMOS. How is 200GHz 100GHz? And no, this does not mean it can switch this fast. If it can switch this fast, it would likely operate into the THz, and we would be interested in using it for THz applications. Maybe operate is maximum stable oscillation frequency? Ft? Fmax? It's sure as hell not a switching frequency, despite what the article tells us.

    "Growing transistors on a wafer not only leads to better performance, it's also more commercially feasible"

    Growing transistors on a wafer? As compared to what? A waffle?

    Done reading... moving on...

  9. Interconnects by John+Hasler · · Score: 3, Interesting

    Graphene will probably be at least as important as a replacement for metallic interconnects as for transistors. Much of the area of a chip is covered by interconnects they are responsible for much of the heat and delay.

    --
    Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
  10. Military Application? by kiehlster · · Score: 2, Insightful

    I have my doubts on whether we'll ever see this because of two things from the article: "first applications of graphene transistors will likely be as switches and amplifiers in analog military electronics" and "Graphene's properties are very sensitive to its environment". This means IBM is placing dainty technology into the hands of the harsh military environment. I've heard how rigorously they test military electronics, and if Graphene is sensitive enough to require insulation, then it's never going to make it past those extreme environment tests they do. Has anyone else seen sensitive materials make it through military applications?

    1. Re:Military Application? by derGoldstein · · Score: 3, Funny

      You're assuming that the transistors themselves will have to go into a hostile environment. Some of them do, but when you're talking about HPC then they'll probably be in a remote location, safe and protected (like Cheyenne Mountain, maybe near the Stargate...).

      --
      Entomologically speaking, the spider is not a bug, it's a feature.
    2. Re:Military Application? by Anonymous Coward · · Score: 2, Informative

      They mean the gate dielectric (which is used for the majority of transistor designs, silicon or otherwise) not that the transistors need insulation from the environment - graphene is more sensitive to the dielectric material (ie the enivronment around the transitior) than silicon. Extreme external (ie military) environment is irrelevant as the entire chip is packaged up anyway.

  11. silicon on sapphire by confused+one · · Score: 3, Insightful

    http://en.wikipedia.org/wiki/Silicon_on_sapphire

  12. 9x faster, not 10x faster by noidentity · · Score: 3, Informative

    The prototype devices [...] can switch on and off [...] about 10 times as fast as the speediest silicon transistors.

    These transistors are only about 9x faster than silicon, not 10x faster as the Slashdot headline claims.

    1. Re:9x faster, not 10x faster by Just+Some+Guy · · Score: 5, Funny

      These transistors are only about 9x faster than silicon, not 10x faster as the Slashdot headline claims.

      Oh, well, in that case don't even bother.

      --
      Dewey, what part of this looks like authorities should be involved?
  13. hold yer horses by lurgyman · · Score: 5, Informative

    Before you get yourselves worked up, realize there is no mention in this article or the original article in "Science" for applying this for computing. There's somewhat of a misstatement in the technology review article - if you look at the actual article in Science (http://www.sciencemag.org/cgi/content/abstract/327/5966/662), the 100GHz figure is the unity (or cutoff) gain frequency (e.g., how high of a frequency you can build an amplifier) and not switching. There is no mention of switching in the paper by the IBM scientists, and that is the application relevant to computing. Even TFA's expert is talking about using this in analog communication frontends, folks. Sorry.

  14. Silicon is still faster by MattskEE · · Score: 2, Interesting

    Graphene is still very much a lab technology which isn't anywhere near ready for commercial production of devices. It may turn out to replace Silicon one day, but guess what, people keep doing amazing shit with silicon because it's still the cheapest material system for fabrication.

    Apologies to those without IEEE access, but here is a paper discussing a recent 150GHz Silicon CMOS amplifier: A 1.1V 150GHz amplifier with 8dB gain and +6dBm saturated output power in standard digital 65nm CMOS using dummy-prefilled microstrip lines. That's pretty awesome in my book. It's pushing the amplifier very close to fmax of the actual transistors, but it works and it's in a commercial silicon process.

    There are always applications where we can do better systems with more expensive materials like GaAs, GaN, InP, Graphene, etc... but silicon is cheap and easily mass-produced, so lots of engineers work on pushing it to incredible performance.