So I wonderwhat all this means for those of us with CP?-Gary


On Thu, 18 Oct 2001, Catherine Alfieri wrote:

>
>
>
> Precursor to Tiniest Chip Is Developed
>
> October 18, 2001
>
> By KENNETH CHANG
>
>
>
>
> In an advance that presages the tiniest of computer
> circuitry possible, researchers at Lucent Technologies have
> built a transistor in which the layer that switches
> currents on and off is only one molecule thick.
>
> Dr. J. Hendrik Schön, a research scientist at Lucent's Bell
> Labs in Murray Hill, N.J., said the experiment proved that
> transistors that worked exactly like those in current
> computer chips could be built at the molecular scale.
>
> "It shows what can be the ultimate limit for transistors,"
> Dr. Schön said. The technology is years away from
> commercial applications.
>
> An article describing findings by Dr. Schön, Dr. Hong Meng
> and Dr. Zhenan Bao, all of Bell Labs, appears in today's
> issue of the journal Nature.
>
> "It is really, really nice work that will influence the
> field a lot," said Dr. James M. Tour, a professor of
> chemistry at Rice University. "They hit on something really
> big."
>
> Transistors are essentially voltage-controlled switches. In
> the off state, no current can flow through, which
> represents a "0" in the binary language of computers. When
> an electric field is applied from the side, from a third
> terminal known as a gate electrode, the electronic
> properties shift and current starts to flow: the on or "1"
> position of the switch.
>
> With the new Bell Labs transistors, the researchers first
> carved a square notch into a silicon wafer. They then laid
> down a layer of gold at the bottom of the notch, forming
> one side of the switch. The wafer was then dipped in a
> solution of carbon- based, stick-shaped molecules that
> behave as semiconductors, with the ends of the molecules
> designed to bond to gold.
>
> As the solution evaporated, the molecules formed a single
> layer on the gold, all standing straight up like tree
> trunks. A second gold layer was then added on top for the
> other side of the switch.
>
> The vertical wall of the silicon notch acted as the gate
> electrode, applying the electric current that turned
> current on and off between the gold electrodes.
>
> The layer of carbon-based molecules is less than one
> ten-millionth of an inch thick, far thinner than the
> equivalent structure in current silicon transistors. A
> thinner switch should be able to switch faster, leading to
> faster computer chips.
>
> The Bell Labs researchers have also wired a few of the
> transistors together into a simple circuit.
>
> Current techniques of carving transistor circuits into
> silicon are expected to run into fundamental physical
> limits in 10 to 15 years that will stop further
> miniaturization.
>
> Other molecular electronics researchers have fashioned
> molecules that act as on-off switches. Transistors, with
> the additional gate electrode, also amplify the incoming
> signal, which counters the effects of electrical resistance
> as the signals pass through the circuit.
>
> This year, two groups of researchers, one at I.B.M. the
> other at Delft University of Technology in the Netherlands,
> announced that they had built transistors and simple
> circuits out of ultra-thin carbon cylinders known as
> nanotubes. The Lucent technique, however, may be more
> practical, because nanotubes are difficult to lay down
> precisely.
>
> "It's a step above what has ever been done in nanotubes,"
> Dr. Tour said. "Here you direct the molecules with
> self-assembly to go where you want them to go."
>
> Dr. Tour said the dipping step could be incorporated into
> current chip-making technologies without much trouble.
> "They built all this upon a silicon platform," he said.
> "This is the marriage you want."
>
> While the switching layer in the prototype transistor is
> only one molecule thick, it still contains several hundred
> thousand molecules. Lucent officials hinted that further
> advances were imminent as they work to shrink the number of
> molecules in the switching layer.
>
> "This is just the beginning of a revolution," said Dr.
> Federico Capasso, vice president for physical research at
> Bell Labs.
>
> Shrinking transistors is not a solution by itself, said Dr.
> R. Stanley Williams, director of quantum science at
> Hewlett-Packard Laboratories in Palo Alto, Calif. If
> trillions of molecule-size transistors could be made,
> trying to wire them together could be an intractable mess.
>
> http://www.nytimes.com/2001/10/18/science/18TRAN.html?ex=1004394494&ei=1&en=
> bbd26de1e37f291e
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>
>
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