Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
Hardware Science

First Graphene Transistor 83

An anonymous reader writes "UK researchers are announcing the first ever workable transistor made of graphene — that's one layer of carbon atoms. It's thinner and smaller than a silicon transistor can ever be, and it works at room temperature. When silicon electronics are dead, this is what many speculate is going to take over. There's slight controversy as they decided to announce their results via a review article, rather than wait for their (submitted) peer review paper to come out."
This discussion has been archived. No new comments can be posted.

First Graphene Transistor

Comments Filter:
  • No Waiting? (Score:2, Insightful)

    by arootbeer ( 808234 )
    No problem...that just means somebody else has built the same thing.
  • by Anonymous Coward on Wednesday February 28, 2007 @06:30PM (#18187370)
    Thank you and goodnight! :)
  • by timeOday ( 582209 ) on Wednesday February 28, 2007 @06:34PM (#18187410)
    Wow, silicon will never match that! Now I don't have to work in this darn freon chamber all day.
    • Just need to invent a catalytic converter-like doo-dah that you fit to the tailpipe of your Hummer.

      Gas in, horsepower and transistors out!

    • by wass ( 72082 ) on Wednesday February 28, 2007 @07:37PM (#18188174)
      You know of a silicon single electron transistor [wikipedia.org] that also works at room temperature? I know some groups have made room-temperature quantum dots previously, but I don't know of any silicon ones. Those other room-temp ones are carbon nanotubes with nano-leads spaced about 10nm apart, in which case they're really graphene already.

      Anyway, graphene has a number of very interesting properties, such as its band structure which looks like a Minkowski space-time cone (or MCP from Tron). Graphene is such that its Fermi energy lies exactly at the cone intersection, and is a so-called zero bandgap semiconductor. Density of states around these conical regimes open up all sorts of applications.

      Interesting story, one group in physics spent lots of time and $$$ trying to make a nano-pencil to try to create a single graphene layer. Ie, they put a chunk of graphite on an AFM tip, and tapped it onto a substrate, making the world's smallest pencil, and thought they may have had a few areas where the resulting line was single layer thick.

      In one of the ultimate cases of getting scooped, a competing team from Harvard took a pencil, scribbled on a piece of paper, and used scotch tape to tap down on the pencil marks. Then tapping that tape onto another substrate gave large areas which had single graphene layers. So the first group was scooped by a team that used literally pennies worth of materials on a process that takes only minutes, while they spent over a year and tens of thousands of dollars on the nano-pencil technique! Cue cliches about thinking outside the box.
  • controversy (Score:4, Insightful)

    by esocid ( 946821 ) on Wednesday February 28, 2007 @06:34PM (#18187416) Journal
    I don't really see it as that controversial. If their research doesn't hold up under peer-review it's their loss, although I am very surprised that Nature is publishing this without it being reviewed. Let's hope it doesn't turn out to be a clone (pardon the pun) of what happened in the faked S. Korean cloning research.
    • In addition it is quite common for this to happen. I'm not saying that justifies the procedure, however it does seem strange that this research in particular is so prominently specified as being 'controversially' released.

      Surely it would have been better for the summary to contain a bit of actual detail on the article rather than just the author's speculation and a slightly over-the-top criticism of the release procedure.
    • by Kadin2048 ( 468275 ) <.ten.yxox. .ta. .nidak.todhsals.> on Thursday March 01, 2007 @02:59AM (#18191540) Homepage Journal
      I agree. I don't understand what's so controversial about releasing a paper via multiple routes. The onus would be on the researchers; if they release via a peer-reviewed journal, while also publishing some other way, and then it's rejected during the peer review, well, they'd look pretty stupid then, no?

      That's not very "controversial." It's ballsy, and arguably arrogant and stupid, but I don't think there's anything particularly wrong with it. Personally, I'd like to see more science be published outside expensive peer-reviewed journals, where regular folks can have access to it without going through complicated databases. At the same time, I understand the purpose that peer-review serves, and we don't want to eliminate that along the way.

      I'm particularly galled by journals that demand exclusivity agreements in order to accept papers for publication, or have gag rules that quash discussion of papers that are being reviewed. That seems contrary to the collaborative nature of science and generally counterproductive (as well as just generally creepy and fascist; I don't much like the idea of anyone telling me that I can't talk about stuff, particularly if I were someone who'd just spend years working on it).

      The only thing I think is a little controversial -- and I'm not even sure I'd choose that word, maybe just "inadvisable" -- is that Nature seems to be going ahead and running the non-reviewed version, even though they could just wait and see a little longer, and make sure that it doesn't get rejected. If a flaw is discovered during the peer review, now it's not just the researchers that are going to look dumb, but anyone who printed the un-reviewed version.

      To say that there's "controversy" about the way they released the article seems to imply that there's tension between peer-reviewed and standard modes of publication, and I think that tension is mostly manufactured or artificial. There's no reason why both modes of publication can't co-exist and compliment each other.
    • Re: (Score:3, Insightful)

      I think it is a bad thing because it will, if it becomes widespread, wind up damaging the reputation not only of the researchers involved, but of scientific publication as a whole. Widespread publishing outside of peer-reviewed channels will inevitably lead to more high profile retractions and publication of faulty science. This will cause people who are not peers (in the sense of peer-review) to be less certain that what they read in a scientific publication is accurate. Peers of course will still be ab
  • practical? (Score:4, Insightful)

    by wizardforce ( 1005805 ) on Wednesday February 28, 2007 @06:38PM (#18187450) Journal
    graphene transistors need to be able to be mass-produced, scalable and just as reliable as alternatives [silicon, quantum computers etc.] most importantly, relatively easy to make- [why diamonds though semiconductive are by no means replacing silicon] it will be interesting to see how this competes in the future though.
    • Re:practical? (Score:5, Insightful)

      by Chris Burke ( 6130 ) on Wednesday February 28, 2007 @06:48PM (#18187586) Homepage
      Yep, those are all realistic concerns and issues that must be addressed before this will really become a silicon killer.

      At the same time, look at the amazing technology that goes into producing silicon chips today. Something that seems ludicrous to mass produce today may just take a decade or so of process and manufacturing technology advancements. On the other hand more research will also probably give silicon a longer life than what anyone predicts (since the death of the silicon CMOSFET has been predicted for decades).

      So I agree, what comes in the future will be interesting.
      • Re:practical? (Score:5, Insightful)

        by MindKata ( 957167 ) on Wednesday February 28, 2007 @07:15PM (#18187942) Journal
        I really hope the technology works but I have doubts about its reliability outside the lab.

        Its one thing getting one transistor working in ideal conditions ... its another to build a circuit with at least a billion of these transistors (which it will need, if it is to compete with Silicon for Computer parts). Although that said, as these transistors will be so fast, there could be more practical high frequency analogue applications.

        I think background radiation will be one of its main reasons it will fail for a CPU and RAM. With a structure 1 atom thick there is no room for failure. Either an atom exists or it doesn't. Knock an atom out of place then it fails. With a conventional transistor as its bulk material all that happens is it degrades its performance but it can take it (most of the time).

        When I first started to read the article I thought it sounded a bit like the Ballistic transistor. Its interesting the Wiki also mentions Graphene as a way to form Ballistic transistors. http://en.wikipedia.org/wiki/Ballistic_transistor [wikipedia.org]

        I really hope it works as it could create incredible computers ... But even analogue applications could be very interesting (like maybe even operating in the Terra Hz range :)
        • Re: (Score:3, Informative)

          by Chris Burke ( 6130 )
          I think background radiation will be one of its main reasons it will fail for a CPU and RAM. With a structure 1 atom thick there is no room for failure. Either an atom exists or it doesn't. Knock an atom out of place then it fails. With a conventional transistor as its bulk material all that happens is it degrades its performance but it can take it (most of the time).

          That's true, and actually with current silicon device sizes a single alpha particle strike has the possibility of flipping a bit in an SRAM.
          • Re:practical? (Score:4, Informative)

            by crgrace ( 220738 ) on Thursday March 01, 2007 @09:27AM (#18193040)
            That's true, and actually with current silicon device sizes a single alpha particle strike has the possibility of flipping a bit in an SRAM. This is one part of why NASA uses old cpus -- one of the simplest methods of radiation hardening is to simply use larger structures that require a larger amount of energy to change state. Then they add more shielding and such on top of course.

            That's actually not true at all. The chance a transient error (SRAM bit flip) or worse, a long term change in the threshold voltage of a device actually gets worse when the structures are larger. That is because the chance for a radiation event to occur in the gate oxide is linearly proportional to the thickness of the oxide. Fine-line CMOS has thinner oxides, so it is more tolerant.

            On top of that, what you are discussing (shielding, structure geometry) is called radiation tolerance, not radiation hardening. A radiation hard IC process implies dielectric isolation between the devices. For example, the use of SOI is quite prevelent in nuclear/space applications. The reason NASA uses old CPUs is because they are available in rad-hard dielectrially isolated technology. Intersil in Palm Bay, FL, still has rad-hard 286s coming off the line right now. Dielectrically isolated IC processes with the feature sizes needed to produce modern CPUs simply do not exist because of the lack of an economic incentive. That is the only reason NASA and DOD use such old CPUs.
        • Re:practical? (Score:4, Insightful)

          by dimeglio ( 456244 ) on Wednesday February 28, 2007 @07:49PM (#18188356)

          I think background radiation will be one of its main reasons it will fail for a CPU and RAM. With a structure 1 atom thick there is no room for failure. Either an atom exists or it doesn't. Knock an atom out of place then it fails. With a conventional transistor as its bulk material all that happens is it degrades its performance but it can take it (most of the time).


          Think how much redundancy you can build into devices of that size. You can have thousands of quantum based CPU's each of them redundant and part of an array for less than the size of current devices. Decisions could be consensus based thus eliminating rogue CPUs for example.
        • Re: (Score:2, Insightful)

          by TheUser0x58 ( 733947 )

          I think background radiation will be one of its main reasons it will fail for a CPU and RAM. With a structure 1 atom thick there is no room for failure. Either an atom exists or it doesn't. Knock an atom out of place then it fails. With a conventional transistor as its bulk material all that happens is it degrades its performance but it can take it (most of the time).

          Can't that be managed with error correction? If you can run these redundantly 1000 times, still be faster and smaller than silicon, and ha

        • Re: (Score:2, Informative)

          by Joe Dutch ( 1009125 )
          In fact that's the beautiful, and arguably the most perplexing, thing abbout graphene. Charge carriers travel thousands of interatomic distances without scattering, even when under 'dirty' conditions. Adsorbates, proximal substrates, lattice vibrations, none of these seems to phase the carriers in their passage from one place to another. This is truly astounding, and we really don't yet know why. But it does suggest that this is one less big thing to worry about when it comes to making devices.

          Moreover, gra
    • by Rosco P. Coltrane ( 209368 ) on Wednesday February 28, 2007 @06:48PM (#18187590)
      need to be able to be mass-produced, scalable and just as reliable as alternatives [silicon, quantum computers etc.]

      John Connor, is that you? I gotta tell you, when you come from, quantum computers might be mass-produced, scalable and reliable, but today they aren't just yet...
    • Re:practical? (Score:4, Informative)

      by cyfer2000 ( 548592 ) on Wednesday February 28, 2007 @07:06PM (#18187826) Journal
      There are two ways to make graphene I have known, one is to exfoliate graphite [wikipedia.org] and the second one is to produce an oversaturated silicon carbide single crystal [sciencemag.org], and the graphene will grow epitaxially from the carbon layer on the surface of the silicon carbide crystal. None of these two can be "practical" IMHO. I also believe the researchers claim the new transistor is "practical" just to differentiate them from the old [gatech.edu] ones [whatsnextnetwork.com]. Anyway I will read the real paper on Nature Materials and see what Novoselov's group has done this time.
    • Re: (Score:2, Interesting)

      I'd be curious to see how they deal with electron tunneling, one layer of atoms doesn't sound very stable.
      • Yes, and at room temperature, no less. The hotter (or faster-moving, if it's got some velocity) the particle is, the better its chance of tunneling out of a potential well.
  • FINALLY... (Score:4, Funny)

    by Penguinshit ( 591885 ) on Wednesday February 28, 2007 @06:47PM (#18187564) Homepage Journal
    A use for Folgers.

    oh, wait; GRAPHene... oops.
  • by theshowmecanuck ( 703852 ) on Wednesday February 28, 2007 @06:47PM (#18187568) Journal

    Current industry predictions suggest that by 2020 silicon devices will have shrunk to about 20 nanometres... ...after this ... graphene will come into their own. And that gives scientists time to perfect the tricky fabrication methods...

    I think if this is to be used in consumer products, market forces will tell them how long they have. Big leaps often come in short time spans. 13 years is a long time and it seems the longer we wait for something to come to market, the more likely it seems to be vapour ware. If this is pure research, they can take their time (and pure research is a good thing too).

    • Re: (Score:3, Funny)

      by Penguinshit ( 591885 )
      Duke Nuke'em Forever is pure research... yeeeaahh; that's the ticket.
    • Re: (Score:3, Insightful)

      by julesh ( 229690 )

      Current industry predictions suggest that by 2020 silicon devices will have shrunk to about 20 nanometres... ...after this ... graphene will come into their own. And that gives scientists time to perfect the tricky fabrication methods...

      I think if this is to be used in consumer products, market forces will tell them how long they have. Big leaps often come in short time spans. 13 years is a long time and it seems the
      • Re: (Score:3, Insightful)

        Comment removed based on user account deletion
        • Re: (Score:3, Insightful)

          by drinkypoo ( 153816 )

          Not many people can see the bigger picture on here.

          But lucky for you, one more arrogant ass will typically pass without comment.

          But not today! Welcome to the club.

    • by Bender_ ( 179208 ) on Wednesday February 28, 2007 @07:32PM (#18188134) Journal

      The node is supposed to be the 22nm node and is only two shrinks away. This means the big companies are hiring R&D personal for that node right now, we are not talking about 2020.

      I would not be worried about physics, but rather about economics. Currently many big companies are exiting process development and cutting edge manufacturing and start to rely on foundries. And we are talking top10 companies: Texas Instruments (inventor of the IC!), Sony, Infineon, Cypress, NXP (Philips), NEC (to some extend). The number of foundries supplying the most advanced manufacturing processes is much less than the number of companies quitting development - maybe 3 to 4.

      Less parallelism in development means that there is less variety, which will lead to a slowdown. Also the funding for R&D at tool vendors will reduce as a direct consequence of having fewer people buying experimental tools. By the time the graphene transistor would be ready there may very well be just one or two companies being able to make use of it..

      • Intel, IBM, AMD, Chartered, TSMC. Who am I missing? And, can anyone specifically rank them in terms of lag behind Intel in months/process generation?
        • by Bender_ ( 179208 )

          IBM,AMD and IBM,Chartered are part of a development alliance so their strategies are pretty similar. You forgot UMC.

    • Re: (Score:1, Insightful)

      by Anonymous Coward
      "Big leaps often come in short time spans"

      Quite the opposite - it may appear that they do - but for (almost) all complex modern technological advances they require many many years of research, planning, problem solving and development before they have something that is consumer grade.

      20 Years may be on the upper end of things, but I can speak from my own research area that OLED technology has been in serious development since the early nineties, and it is only in the last couple of years that we have seen c
  • I saw the main page, and I thought it read:

    "First Graphene Calculator"

    Which would make sense, as that's basically what transistor does, only it's been done already...

    I know, I know, I know...
  • by nuzak ( 959558 ) on Wednesday February 28, 2007 @06:54PM (#18187664) Journal
    When silicon electronics are dead, this is what many speculate is going to take over.

    One of the disadvantages of using Firehose is seeing idiotic asides like this inserted into submissions, but knowing that it'll make the front page anyway, and also knowing that absolutely no editing will be done.

  • Lets see if they can actually figure out how to mass produce it first. This sounds a lot like carbon nanotubes to me...good on paper, but essentially vaporware in the minds of consumers and manufacturers.
  • Impressive (Score:2, Interesting)

    by bendodge ( 998616 )
    Couple that with these [technologyreview.com] nanometer-scale silicon lasers (made with standard chip fabrication), and Moore's law will definitely survive. Our current tech will look like molasses when these are coupled.

    Imagine fiber optic motherboard traces with chips made out of graphene. It might to move us to counting in terehertz.
    • Re: (Score:3, Informative)

      by PhysicsPhil ( 880677 )
      The Intel work you reference is just bonding an indium phosphide laser chip onto a silicon wafer, not actually creating a silicon laser by itself. While a Raman laser has been produced in silicon, the real device of interest, an electrically pumped diode laser is still the stuff of dreams.
    • Obligatory (Score:3, Funny)

      by Dunbal ( 464142 )
      [Graphene....]nanometer-scale silicon lasers... Our current tech will look like molasses when these are coupled.


            Just wait till you see what happens when they start adding the sharks...
      • Too bad I just lost some mod points.....I didn't see that comment coming and it brought a much needed chuckle to my day.
  • I mean, the article's about a completely flat sheet of atoms joined in a structure with four edges from each node.

    So, why are they showing a ripply surface made from a hexagonal structure, with three edges from each node?
    • by julesh ( 229690 )
      OK, just chasing up my references, seems hexagonal is correct. But still -- why ripply? It's supposed to be *flat*. That's *the point*. :)
      • TFA talks about ripples and the picture is captioned "graphene is not entirely flat". Anyway, consider the scales here, the sheets are less than an angstrom thick, and that's being generous.
      • Re: (Score:1, Informative)

        by purify0583 ( 1063046 )

        Perfect graphene is flat. But any imperfections caused by a missing carbon or an extra carbon will cause it to bend slightly. Which would explain the ripples.

        Source from wikipedia :

        Perfect graphenes consist exclusively of hexagonal cells; pentagonal and heptagonal cells constitute defects. If an isolated pentagonal cell is present, then the plane warps into a cone shape; insertion of 12 pentagons would create a fullerene. Likewise, insertion of an isolated heptagon causes the sheet to become saddle-shaped. Controlled addition of pentagons and heptagons would allow a wide variety of shapes to be made.

    • by PhysicsPhil ( 880677 ) on Wednesday February 28, 2007 @07:26PM (#18188062)

      I mean, the article's about a completely flat sheet of atoms joined in a structure with four edges from eac node. So, why are they showing a ripply surface made from a hexagonal structure, with three edges from each node?

      As you note in your follow-up post, the hexagonal bonding structure is correct for graphene. The rippling motion is a result of thermal fluctuations. Normally you don't see it much because the graphene is bonded to a substrate, but as the second link in the main article explains, free standing membranes do actually ripple.

      • Re: (Score:1, Interesting)

        by purify0583 ( 1063046 )

        FT*2nd*A:

        One of graphene's simplest properties - that of being a perfectly flat 2D sheet - is the most mystifying of all, said Geim. In theory, thermal fluctuations should cause any perfect 2D crystal to vibrate out of the plane, with sufficient energy to break its bonds. Scientists had surmised that graphene could only appear both stable and perfectly flat because it was usually stabilised on a substrate.

        But in Nature this week, Geim's team also reveals that the supposedly flat sheet is in fact corrugated; tiny ripples of graphene crystallites make the sheets 3D when suspended in isolation

        The article explains that free standing graphene could not exist on its own if it was not intrinsiclly rippled. What they discovered was that graphene actually has a rippled structure when isolated which allows them to use it in such a fashion. So its my understanding that thermal fluctuations are not the cause of the ripples, instead something in the nature of graphene is. It would be nice it they would explain why it is rippled. Is it because of imperfections or simply the nature of the s

        • Re: (Score:3, Interesting)

          This is only a guess, but I think the ripples might be caused by what are known as Stone-Wales defects, which involve a carbon-carbon bond rotating 90 degrees to convert a local structure of four hexagons into two pentagons and two heptagons. These rings prefer to form "puckered" conformations, which would explain the ripples.

          I think "thermal fluctuations" as a reason for the ripples comes about because these interconversions have a high activation energy, so they are likely to occur only at "hot spots"

  • Great now we're only 2 letters away from Graphite based Transistors
    and as soon as that's ready, grab yourself some epaper and a pencil
    and get ready to design your own quad core 64bit WHSmith CPU
    how about that for Linux from Scratch
    true hardcore means no erasors
  • When I was a grad student at UCLA, a postdoc and I collected some data in lab. The professor decided it would well complement the review article to have this new information. So, it happens, and not necessarily to dodge peer review.
  • In other words, where does this leave our dear friend Hafnium [slashdot.org]?
  • The Carbon atom is around 0.2nm width. If they can make gates with a single atom (lets ignore interconnection),
    this means that we can go up to 0.2nm (This is just 8 generations away from 45nm or less than 20 years).

    I guess that to keep the Moore's law, we'll go to 3D chips much earlier (my 2 cents that we'll have mass
    produced 3D chips before or during 22nm).
  • Peer Review! (Score:2, Informative)

    by drolli ( 522659 )
    Peer Review is a very important thing. Not only it prevents some bad reseaarch from entering Journals, but it actually increases the quality of articles published - because Referees ask meaningful Questions, whcih can help to clarify unclear points.
  • .. although it's going to take an awful large layer of 1-atom thick carbon to remove all that CO2 from the atmosphere.
  • Didn't Georgia Tech make a Hall Effect Transistor out of Graphene back in March? This is impressive, but hardly "the first"...
  • it works at room temperature

    That may be well and good, except that most chips are running at 55C. and above. That's not my room temperature.

It is easier to write an incorrect program than understand a correct one.

Working...