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Science Technology

Aussie, Finnish Researchers Create a Single-Atom Transistor 96

ACKyushu writes "Researchers from Helsinki University of Technology (Finland), University of New South Wales (Australia), and University of Melbourne (Australia) have succeeded in building a working transistor whose active region comprises only a single phosphorus atom in silicon. The results have just been published in Nano Letters. The working principles of the device are based on sequential tunneling of single electrons between the phosphorus atom and the source and drain leads of the transistor. The tunneling can be suppressed or allowed by controlling the voltage on a nearby metal electrode with a width of a few tens of nanometers."
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Aussie, Finnish Researchers Create a Single-Atom Transistor

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  • by mangu ( 126918 ) on Sunday December 06, 2009 @06:53AM (#30342314)

    Well, at least this seems to set an ultimate limit to Moore's law, since it's not very easy to go to less than one atom per transistor.

  • Cosmic rays (Score:3, Interesting)

    by Alain Williams ( 2972 ) <> on Sunday December 06, 2009 @07:47AM (#30342474) Homepage
    If the state of a gate depends on one electron, it will be highly sensitive to radiation. So what do we do ? Embed these in large blocks of lead ?
  • by Ancient_Hacker ( 751168 ) on Sunday December 06, 2009 @08:42AM (#30342638)

    This thingy is just a research device, just good for research. It's not a precursor of anything practical.

    It's been known for many, many years that there are serious tradeoffs to be pondered when you shrink transistors (and FETs).

    Your basic linear dimension versus surface area versus volume scaling laws are in full play here.

    You win at first, as smaller base or gate lengths lead to more speed, and less surface area means less capacitance to charge up.

    But below a certain size the rapidly shrinking cross-sectional area reaches its current-carrying capability, while noise and leakage loom large.

    Right now the low-level chip designers, with their 10^12 atom transistors are already spending a large part of their time with these issues. The challenges are not going to go away, they just get larger as one attempts to shrink things even more. It's unlikely that these hard challenges can be overcome to span the million-million times distance to a true one-atom transistor.

      So don't put any big money on ever having one-atom transistors in any practical device.

  • by mangu ( 126918 ) on Sunday December 06, 2009 @10:06AM (#30342936)

    So don't put any big money on ever having one-atom transistors in any practical device.

    I'm old enough to remember when people said no dynamic memory chip could ever be made with more than 64 kilobits capacity. The capacitor charge would be flipped by radiation hitting the chip [].

    Probably this is the origin of the "640 kbytes should be enough for anybody" meme, since, with 64 kbit chips, it would be difficult to pack more than the 80 chips needed for 640 kbytes in a desktop computer.

  • by Anonymous Coward on Sunday December 06, 2009 @10:43AM (#30343108)

    Just curious, but how would something like get of the ground? How owuld an australian and finnish university cooperate, and why?

  • by Bruha ( 412869 ) on Sunday December 06, 2009 @01:13PM (#30343990) Homepage Journal

    10GHz cores are not something you want to sit next to without proper shielding it's possible you could be burned. It was a concern back when we were approaching single core 5GHz before the dual core processors came out and everyone was speculating we would be at 10GHz in 3-5 years. That was about 6 years ago I believe.

Q: How many IBM CPU's does it take to execute a job? A: Four; three to hold it down, and one to rip its head off.