Follow Slashdot stories on Twitter

 


Forgot your password?
Close
typodupeerror
×
Technology Science

Branched Nanotubes Offer Smaller Transistors 218

Posted by CmdrTaco from the it's-a-good-size dept.
Designadrug writes "Tiny tubes of carbon, crafted into the shape of a Y, could revolutionize the computer industry, suggests new research. The work has shown that Y-shaped carbon nanotubes are easily made and act as remarkably efficient electronic transistors - but the nanotransistors are just a few hundred millionths of a meter in size -roughly 100 times smaller than the components used in today's microprocessors."
This discussion has been archived. No new comments can be posted.

Branched Nanotubes Offer Smaller Transistors More

Branched Nanotubes Offer Smaller Transistors

Comments Filter:

  • Moore's Law. (Score:5, Interesting)

    by Quebec ( 35169 ) * on Tuesday August 16, 2005 @10:32AM (#13330624) Homepage
    Each time some expert's saying that Moore's Law is about to hit a barrier,
    there is something going on like those promising nanotubes.

    Another one for Moore against those doomsday preacher like this one:
    http://news.zdnet.com/2100-9584_22-5112061.html [zdnet.com]

    • And the best part? (Score:2, Funny)

      by Anonymous Coward
      Soon we'll have cell phones we can lose *100 times* as fast!
      • Actually, Cellphone-Losing is a function of volume, not length. So size should decrease by a factor of 10000000 (100^3).
        • That's a worst case scenario. It's far more likely to scale like the area since as yet we have no truely volumetric ICs.

          So cellphone-losing (or my favorite, accidental washing & tumble dry) should increase by only a factor of 10k.

          • Re:And the best part? (Score:3, Insightful)

            by drakaan ( 688386 )
            Actually, you're both off a bit.

            In TFA, the "100 times smaller" comes from the length of the nanotube transistor being 1/10th that of its silicon counterpart. Cellphone-losing should increase by no more than a factor of 100 (unless 3-d chips become commonplace).

    • Re:Moore's Law. (Score:2, Insightful)

      by Anonymous Coward
      Well, they still need to develop an industrial process for putting billions of those things cheaply on a small chip. That will take decades, at the very least, and in the time the current CMOS chip technology will have advanced several times... Don't hold your breath.
      • and in the time the current CMOS chip technology will have advanced several times

        DOH. There ARE already nanotube transistors using single nanotubes. ALREADY the work is done on integrating these on very large scale.

        If they know how to attach a nanotube to a layer of silicon to make a transistor, don't you think they'l know how to attach a branched nanotube to make a full circuit?

        Take a look at the industry. 2 years ago it was discovered that silver nanostructures were antibiotic. Today, LG gives us fridges
        • If they know how to attach a nanotube to a layer of silicon to make a transistor, don't you think they'l know how to attach a branched nanotube to make a full circuit?

          There is no known way to build large numbers of nanontube transistors with good yield. What can be done so far is attaching single nanotubes somewhere and measure lots of devices until you find a good one.

          Remember: To build a state of the art CPU you have to produce more than 1e8 transistors with exactly 100% yield.

    • Re:Moore's Law. (Score:4, Funny)

      by slapout ( 93640 ) on Tuesday August 16, 2005 @10:36AM (#13330667)
      Hey, you could have your own law:

      Quebec's law: "Each time some expert's saying that Moore's Law is about to hit a barrier,
      there is something going on like those promising nanotubes."
      • Hey, you could have your own law: Quebec's law: "Each time some expert's saying that Moore's Law is about to hit a barrier, there is something going on like those promising nanotubes."
        Sorta like Slapout's Corollary: "Anytime something can go wrong, no matter how likely, something will eventually come along and make it actually work, defying all odds and logic."

        i think metamoderation works something like that...

    • Re:Moore's Law. (Score:5, Insightful)

      by LWATCDR ( 28044 ) on Tuesday August 16, 2005 @10:41AM (#13330702) Homepage Journal
      Except one of the reason Moore's observation held is that ICs are so much easier to make then what they replaced. These new nanotubes may not scale to well for mass production.
      Moore's law IS not a fundamental law of the Universe. It was an observation of a trend that has held up for a lot long than anyone expected.
      • It's actually a matter of economics more than anything else. The theory is available now for Moore's law to continue for a decade or two, and new theory seems to get worked out regularly; the fundamental limits are a long way off. What makes Moore's law relatively regular is that it takes a certain amount of development effort to get the new techniques into chips, and that rate of improvement is the minimum needed to get people to buy your chips.
      • These new nanotubes may not scale to well for mass production.

        Anything that can be manufactured by man can be scaled to mass production (like jet aircraft, complex chemicals, atomic bombs and ICBMs for example). It's just a matter of how much resources you are willing to put into it, and even then it might not be economical.

        I think Moore's law will be sustanible if there is economic demand for faster chips. If they can't get the Hz faster they'll scale outwards (dual cores and parallel processing route)
      • Moore's law is NOT a fundamental law of the Universe. It was an observation of a trend that has held up for a lot longer than anyone expected.

        Indeed, Moore's law isn't as certain as sunrise... and even that will eventually run out...

        But its longevity does suggest that more than a mere circumstantial trend may be at work... say, something closely related to the exponential growth of scientific knowledge. Nanotubes look like they'd fit that bill nicely.

    • Re:Moore's Law. (Score:4, Interesting)

      by Anm ( 18575 ) on Tuesday August 16, 2005 @10:46AM (#13330751)
      Actually.. the sizes mentioned in the Moore's Law barrier article you linked to roughly equate to the "a few hundred millionths of a meter in size" (2/100,000,000 meters == 20 nano-meters ~= 16 nanometers). Since the barrier is over a decade away, the two articles aren't in conflict, as much as you would like to hope.

      Anm
      • I think that moore's law has already stopped and someone needs to get it going again. After all the billion bit chip was mass produced in 1999 therefore the 2 billion should have been in 2001 with the 4 billion in 2003 and the 8 billion in 2005. I just hope that they stop making processors with only one on a chip and make the duo processors as cheap as the single ones are today.

    • Re:Moore's Law. (Score:5, Informative)

      by fbjon ( 692006 ) on Tuesday August 16, 2005 @10:52AM (#13330794) Homepage Journal
      There was an article in Sientific American [sciam.com] about making chips much smaller by letting water flow between the imprinting laser lens and the silicon wafer. The water changes the refractive index, so the lens can be better utilized, as I understand it, and apparently it's not particularly difficult either, since existing 193nm lithography can be used, and even surpass the planned 157nm lithography tech. Here's another article with some links [geek.com].

      • do more with less (Score:2, Interesting)

        by wimp_org ( 896474 )
        Now that you mentioned SCIAM.
        There is an article in the august issue of Scientific American [sciam.com] about magnetologic gates. This mentions that instead of making transistors smaller so you can put more of them in the same space. You could also try achieve the same functions using less elements.

        magnetologic gates are based on the MRAM technology [ibm.com]. With some modifications the designs for MRAM can be used to create logic gates that are much more efficient and powerfull then CMOS based transistors.
        With only 1 magne

    • Re: (Score:3, Interesting)

      by account_deleted ( 4530225 )
      Comment removed based on user account deletion
      • Moore's Law *will* hit the barrier. You cannot make something out matter smaller then an atom. Next step wont be evolutionary, but revolutionary. This is when we get into quantum computing.

        I thought you couldn't make something out of matter smaller than an atom, eh?

        I guess I'm going to have to go disappoint all those quantum computation researchers.

        • I guess I'm going to have to go disappoint all those quantum computation researchers


          Why do I get the feeling that if you can find them, you won't be able to affect their momentum?

      • Then maybe we will have polarized light transistors (switching the polarization of light), with multiple light frequencies.
         
      • When you consider that we're just getting an inkling of what quantum effects are it will be quite some time.

        For example, what happens when we start using the particles, or using the quantum states of those particles?
    • Moore's law is over, or is Intel shipping a 10GHz cpu? Yes, we will probably get faster cores yet, but the days of reliable speed increases are done. Hence the move to multi-core.

      • Re:Moore's Law. (Score:4, Informative)

        by amliebsch ( 724858 ) on Tuesday August 16, 2005 @11:20AM (#13331038) Journal
        Moore's law applies to transistor counts per square inch, not clock speeds. You're thinking of the "Law of Marketing."

      • Re:Moore's Law. (Score:3, Informative)

        by oringo ( 848629 )
        Do you even know what Moore's law is? Even a highschool student can tell you that it has nothing to do with the MHz speed of the silicon, although theoretically as the widths of the gates shrink you can run the logic faster. Moore's Law simply states that the density of silicon chips doubles every 18 month.
        On a sidenote, Intel's Netburst archicture has turned out to be a failure to reliably increase the PERFORMANCE of the CPU (ironically I'm using one right now), precisely because of the architecture's emph
    • It isn't a law, but a prediction made by viewing previous data, that hasn't even held, and gets modified to fit the results.

      Now, check my journal on this, because I really wish people would shut up about moores law.

      It takes credit from the chaps who did the hard thinking to get us to this point, and says, oh well, it was expected anyway.

      Just, aaagh.
    • So in other words the nanotube enabled computer I'm using now will be replaced with a nanotube based computer that is twice as fast in 18 months???

      I thought the key implied part of "improving" was to actually have something to improve upon.

      • So in other words the nanotube enabled computer I'm using now will be replaced with a nanotube based computer that is twice as fast in 18 months???

        No, the nanotube-enabled computer you're using will be replaced by one with twice as many nanotubes per square mm in 18 months.

    • I find your absolute faith in Moore's "Law"...disconcerting.

      What Gordon Moore originally said was the underwhelming

      The complexity for minimum component costs has increased at a rate of roughly a factor of two per year (see graph on next page). Certainly over the short term this rate can be expected to continue, if not to increase.

      (Don't believe me? Read it here [wikipedia.org] instead.)

      By Moore's statement we should be seeing chips with IC counts of 70 trillion (10^13), but the latest Pentium D has a transistor cou

      • The complexity for minimum component costs has increased at a rate of roughly a factor of two per year (see graph on next page). Certainly over the short term this rate can be expected to continue, if not to increase.

        You left out the rest of this quote:

        Over the longer term, the rate of increase is a bit more uncertain, although there is no reason to believe it will not remain nearly constant for at least 10 years.

        This quote was published in 1965. The Wikipedia article continues:

        In 1975, Moore pro

  • Nothing for you to see here. Please move along. (Score:5, Funny)

    by BlackCobra43 ( 596714 ) on Tuesday August 16, 2005 @10:32AM (#13330630)
    What if I have a really, really powerful microscope?

  • Matters of Size and Scope (Score:4, Interesting)

    by ackthpt ( 218170 ) * on Tuesday August 16, 2005 @10:33AM (#13330635) Homepage Journal
    the nanotransistors are just a few hundred millionths of a meter in size -roughly 100 times smaller than the components used in today's microprocessors.

    We're going to have a devil of a time soldering these things, not to mention fitting them with heatsinks...

    Bandaru says the main remaining worry is how to manufacture complex nanotube-based circuitry reliably. Nonetheless, he is optimistic about the future of nanotube-based electronics.

    "One must remember that for the Pentium chips which now have over 500 million transistors, the progenitor was a simple integrated circuit with two transistors in 1958," Bandaru says. "We are probably at the same stage with Y-junctions and the future looks good."
    37 years? I can't wait that long! Where's the Fast Forward on these things?
    • I've already read about good techniques for this. Basically on the board you create sticky points and dip the board into the nanotubes like ice cream into a bowl of sprinkles. Lithography or bacteria or whatever could be used to create special adhesive sights to orient the nanotube. I'm guessing you could dope them with an iron molecule at one end. Sort out correctly oriented nanotubes. Put the lot into a strong magnetic field and create a thin film of evenly spaced particles by using an ultrasonic resonan

  • 9nm? (Score:1, Insightful)

    by Anonymous Coward
    Maybe this is how Intel will get that 9nm process they said they'd have by 2009.
  • But the nanotransistors are just a few hundred millionths of a metre in size -roughly 100 times smaller than the components used in today's microprocessors. They could, therefore, be used to create microchips several orders of magnitude more powerful than the ones used in computers today, with no increase in chip size.

    How about the heat? Anyone? Will it increase by 100? How does the heat production increase with decrease in the size of the components anyway?

    "One must remember that for the Pentium chi
    • decreasing the size of something doesn't increase the heat it produces, no. it makes it harder for said something to dissipate the heat, as it has less surface area. you might be overlooking the part of the blurb that said "are easily made and act as remarkably efficient electronic transistors". remarkably efficient almost implies that heat issues are decreased proportionally to the size. almost. so i'd be more inclined to guess that heat decreases by a factor of 100 before i'd say it increases.

    • Re:size vs heat in 50 years (Score:5, Informative)

      by ajs318 ( 655362 ) <sd_resp2NO@SPAMearthshod.co.uk> on Tuesday August 16, 2005 @11:00AM (#13330853)
      What you have to remember about heat is that electronics only get hot because they are never perfect conductors nor perfect insulators {though we can make nearer-perfect insulators than we can conductors}. A perfect conductor will never get hot, no matter how much current you put through it, because the voltage drop across it will be nil and power = voltage * current. Nor will a perfect insulator, because this time, the current through it will be nil.

      CMOS is based around two transistors, a P-channel FET which goes conductive when the gate is driven low, and an N-channel FET which goes conductive when the gate is driven high. The P-FET is trying to pull the output high and the N-FET is trying to pull it low. Both the gates are joined together, and this is the input. This is a simple NOT gate.

      For a NAND gate, where any input 0 will drive the output to a 1, we have several P-FETs in parallel trying to drive the output high, and so many N-FETs in series trying to drive the output low. Each P-FET gate joined to an N-FET gate is one input. When they are all high, all the N-FETs turn on allowing the output to go low; when any one is low, the chain of N-FETs is broken, one or more P-FETs turn on, and the output goes high. For a NOR gate, where any input 1 will drive the output to a 0, we put the Ns in parallel and the Ps in series. You can make AND gates from NAND+NOT, OR gates from NOR+NOT, and any other combination you like. In fact you really don't need both NAND and NOR, because you can make either one out of the other; but it turns out they're equally as easy to make as each other in CMOS {not like many other technologies}.

      In an ideal world this would never dissipate any power, since the input cannot be high and low at the same time so only one of the transistors will ever be on. In practice what happens is that the gates act like capacitors which take a finite time to charge and discharge. They do not switch instantaneously from conductive to non-conductive. So one stops conducting while the other is starting to conduct, and for a brief instant while the inputs are changing state both transistors are conducting a little. It's not a dead short circuit of course, otherwise something would give way ..... hopefully a fuse.

      Now every time something changes state, you get a little pulse of heat. Which is why fast processors need cooling. Additionally, to make sure that the logic gate output has changed state before the next clock pulse, you need to make the gate capacitances charge up quickly -- which means using a higher voltage than you could get away with at lower speeds. But 2x more volts means 2x more amps means 4x more watts.

      Smaller transistors should have less gate capacitance, and so be capable of switching more quickly.
      • This is a very good summary.

        One additional factor that needs to be added, though, is that as MOSFET transistors scale towards smaller and smaller features, leakage current becomes a larger and larger problem. Basically, at extremely small sizes, quantum effects start to become significant, and electrons randomly tunnel from one end to the other.

        The larger the leakage current, the more is lost to heat.

        It remains to be seen how large a problem leakage current is with the new tube transistors. If it's not a
        • Remember nanotubes can act as near-superconductors. Remember the article on Quantum Wires [slashdot.org]? The leakage will be negligible. Plus, who says nanotube CPU's will have to transport millions of electrons to do a computation? Maybe a few thousands will do the work.
      • Most of the power dissipation occurs in the transistors, not the wires. The power is dissipated more because capacitance is being charged through the resistance of the transistors, than because of simultaneous conduction ("shootthough").

        Although better conductivity in both wires and transistors would be helpful (people cool CPUs to accomplish this), too much can be a bad thing. With no resistance, circuits would ring badly, causing high instantaneous voltage and gate breakdown.

  • Would it look like a tree?

    Would it make a great way to interface with tree-like neural structures?

  • Coming Soon: Time Travel (Score:5, Funny)

    by DaSpudMan ( 671160 ) on Tuesday August 16, 2005 @10:39AM (#13330687)
    Looks like a Flux Capacitor to me.

  • Old News (Score:5, Informative)

    by TripMaster Monkey ( 862126 ) * on Tuesday August 16, 2005 @10:41AM (#13330704)

    This paper [tripod.com] suggests that this sort of thing was being done 5 years ago.

    From the paper:
    Also, Papadopoulos et al introduced a Y-junction formation technique using branched nanochannel alumina templates (Papadopoulos, 2000).

    • Re:Old News (Score:2, Insightful)

      by jda487 ( 646991 )
      Making one 5 years ago and now knowing that it has semi-conductiong properities are two entirely different things.

      • Before commenting, you might want to actually read, or at least skim, the paper I linked to in my original post.

        Fom the paper:

        The nanotubes are characterized by a chiral vector c = na + mb where a and b are vectors defining a unit cell in the planar graphene sheet and n and m are integers. Depending on chirality (i.e., the values of n and m), CNT can be either metallic or semiconducting. If (n-m)/3 is an integer, the nanotubes is metallic; otherwise it is a semiconductor (Dresselhaus, 1996).

    • Creating a Y-junction nanotube is 5 years old. But the news here isn't that they created a Y-junction nanotube.

      The news here is that they created a Y-junction nanotube with a metal particle at the junction which caused it to function as a transistor.

  • "Today, scientists discovered diamond rings smaller than the size of an electron. It is theorized that this can revolutionize microprocessors, electronics, physics as we know it, and apple pie."

    I'm getting a bit bored with these wide remarks saying profound discovery X has been achieved and that it may affect future production of [whatever], when it's so far from even prototype production that the PhD thesis on it hasn't even been written yet.

    Can we get stories with a little more substance? Please?
    • As anybody who's ever been to Wal Mart knows, microscopic diamond rings are in high demand.

    • Dateline 21st February 1953

      Scientists today revealed the molecular structure of DNA. It is theorised that this may revolutionise medical research and forensic science (and posibly Apple Pie).

      And I bet someone said back then all they've done is describe the molecule.

  • A few issues (Score:2, Informative)

    by convex_mirror ( 905839 )
    In the near-term, we have to be able to sort CNTs by chirality and diameter much more accurately and cheaply than we can now - this is because the properties of CNTs change dramatically based on very slight variations in these properties.

    Once we can do that reasonably well, there are a few approaches that look promising. For /. people who have access to scientific journals and want more in depth information on this subect - you can take a look at these articles:
    P. G. Collins, et al., Science, 292, 706
    • "In the near-term, we have to be able to sort CNTs by chirality and diameter much more accurately and cheaply than we can now"

      I doubt bulk production and sorting of nanotubes is going to be of much value. Suppose there IS a particular type that's really great for making circuits. How then do you deposite them and connect them into a circuit? And that will need to be done with individual tubes, not bulk - this article mentions the tubes are about 1/10 the size of present transistors, so if you lay down a b

  • Math (Score:3, Insightful)

    by Anonymous Coward on Tuesday August 16, 2005 @10:48AM (#13330768)
    [B]ut the nanotransistors are just a few hundred millionths of a meter in size -roughly 100 times smaller than the components used in today's microprocessors

    So, uh, they are a few hundred millionths of a meter in size -- or to put it in clearer terms, a few tens of nanometers in size. That'd put them in the 30-60nm range. Intel's currently making chips on a 90nm process, and intends to start making them on a 65nm process by the end of the year.

    That's not a 1/100x size improvement

  • Nano Tubes (Score:3, Funny)

    by devphaeton ( 695736 ) on Tuesday August 16, 2005 @11:09AM (#13330927)
    Yeah, but i still bet nothing switches data as warmly as vacuum tubes...... /me snickers, waits for it.
  • Yes, but is it recursive?

  • It's all in the details, whatever they are (Score:3, Informative)

    by Ancient_Hacker ( 751168 ) on Tuesday August 16, 2005 @12:08PM (#13331472)
    it would be nice if TFA had a few facts comparing these to current transistors. Just being "small" isnt good enough. Quite a few things have to also be in the right range to make them competitive, such as voltage swing, current gain, switching speed, reliability, feedthrough and feedback capacitance, and probably more. And it's a bit presumptuous for anybody to extrapolate these things along the same improvement curve as transistors and IC's.

  • Don't get me wrong... (Score:3, Insightful)

    by teutonic_leech ( 596265 ) on Tuesday August 16, 2005 @12:37PM (#13331707)
    ... I'm all over nanotech - have myself been attending Foresight Institute meetings regularly for the last decade. BUT, since the early nineties I've seen dozens of research papers promising new types of transistors and thus far the problem seems to be mass manufacturing of any of these approaches. What works in the lab is one thing - making a commercial product is another. So, don't get your hopes up to 'upgrade' to a nanochip any time soon ;-) Nevertheless, we're heading in the right direction - this type of research caters to the VC community which is already investing heavily into privately funded nanotech related companies. Heaven knows - here in the U.S. we desperately need this type of research, may it be academically or privately driven. China, Japan, Korea, India, etc.. are catching up quickly and we already lost the race in the biotech and genetic engineering department.

  • Robert Frost (Score:3, Funny)

    by threaded ( 89367 ) on Tuesday August 16, 2005 @01:38PM (#13332190) Homepage
    Two roads diverged in a wood, and I--
    I took the one less traveled by,
    And that has made all the difference.
  • The discovery of Y-shaped nanotubes made water searchers more convinced that using an Y-shaped branch from a tree is the best approach possible.
  • These nanotube transistors are very cheap to make... but they're a bitch and a half getting them to the right spot on the chip and a bugger making them stay there afterwards!

  • Let's Get Small Again (Score:4, Interesting)

    by Doc Ruby ( 173196 ) on Tuesday August 16, 2005 @02:33PM (#13332621) Homepage Journal
    "the progenitor was a simple integrated circuit with two transistors in 1958 ... [w]e are probably at the same stage with Y-junctions"

    Intel debuted the 4004, the first commodity microprocessor chip, in 1971 with 2300 transistors [pcworld.com]. That's 13 years, during which we had a space race (and Minuteman missile [nps.gov] program) to stimulate investment. Today we have $trillions in returns on chip investment as stimulus, as well as an existing investment/manufacturing/marketing infrastructure. As well as highly useful micron-scale chips and software for design. So perhaps we're looking at a breakthrough "nanoprocessor" sometime earlier than 2028.
  • A single molecule transistor would be way smaller than the nanotube one.

    http://www.physorg.com/news4345.html [physorg.com]

  • Meanwhile (Score:4, Funny)

    by Julian Morrison ( 5575 ) on Tuesday August 16, 2005 @04:39PM (#13334008)
    Senior figures in the Bush administration were in talks with scientists, to see if a way could be found to fit these "naked" transistors with trousers.
    • Senior intelligence officials are quoted as saying, "It was just supposed to be a harmless joke. Nobody thought the President would actually believe Iran was stockpiling trousers." Iranian officials, however, are not laughing.

Slashdot Top Deals

Garbage In -- Gospel Out.

Close