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Ohm's Law Survives To the Atomic Level
Hugh Pickens writes "Moore's Law, the cornerstone of the semiconductor industry, may get a reprieve from its predicted demise. As wires shrink to just nanometers in diameter, their resistivity tends to grow exponentially, curbing their usefulness as current carriers. But now a team of researchers has shown that it is possible to fabricate low-resistivity nanowires at the smallest scales imaginable by stringing together individual atoms in silicon as small as four atoms (about 1.5 nanometers) wide and a single atom tall. The secret is to introduce phosphorus along that line because each phosphorus atom donates an electron to the silicon crystal, which promotes electrical conduction. They then encase the nanowires entirely in silicon, which makes the conduction electrons more immune to outside influence. By embedding phosphorus atoms within a silicon crystal with an average spacing of less than 1 nanometer, the team achieved a diameter-independent resistivity, which demonstrates ohmic scaling to the atomic limit. 'That moves the wires away from the surfaces and away from other interfaces,' says physicist says Michelle Simmons. 'That allows the electron to stay conducting and not get caught up in other interfaces.' The wires have the carrying capacity of copper, indicating that the technique might help microchips continue their steady shrinkage over time and may even extend the life of Moore's Law. 'Fundamentally, we have shown that we can maintain low resistivities in doped silicon wires down to the atomic scale,' says Simmons, adding that it may not be ready for production now, but, 'who knows 20 years from now?'"
If the atomic resistance gather together at ohm's law, will they occupy it?
When the foot seeks the place of the head, the line is crossed. Know your place. Keep your place. Be a shoe.
So is it Ohm or Moore?
At first I was thinking they meant Moore's Law and somebody had found a way to make really tiny ultra fast processors. Moore, Ohm, Watt... learned all of their laws in the same class in high school. I really need to take up drinking coffee in the morning.
Likely because I just quit smoking and are somewhat grumpy, but I am tired of hearing about Moore's Law. Maybe those in the semiconductor industry care about it, but I, and those I work with certainly don't. At what point will we stop hearing about it? /rant
(Thank you for your patience. Now where are the damn pretzels?)
... it scale and can you produce it cheaply?
So the Star Trek prediction where computers of the future seem to be full of brightly lit crystals may have been accurate?
Of course it's valid. It's a law! Not some phony-baloney "theory" like evolution or gravity.
Hate to have to solder one :-)
--an unbreakable toy is useful for breaking other toys--
TFA says that the wires were deposited lithographically (the technique currently used to make chips) and then the phosphorus was deposited. So this, in theory, could be done cheaply.
However, TFA also mentions low temperature. It doesn't measure exactly what temperature, but processors are not usually operated at low temperatures. If this is a "liquid nitrogen cold" temperature, then this could very well be useless on a grand scale. But if the effect survives to room temperature (or higher), then this could have a huge impact.
Just a first order approximation would show that these wires are about 5 times smaller than the current 22nm state-of-the-art. In two dimensions, that means roughly a 2500% increase in density, enough to keep Moore's law alive and well for some time to come.
Great warrior...hrmph! Wars not make one great.
The resistance of interconnects grows polynomially, not exponentially, as they decrease in size.
It's an important difference. As sizes get small enough, we start to see stochastic effects, but we're not there yet.
Don't take life too seriously; it isn't permanent.
Ohm's Law is my favorite law.
Moore pics please.
Now we have to worry about shrinkage? Maybe the microchip was in the pool
I don't know the meaning of the word 'don't' - J
The wires are composed of doped silicon, and features of doped silicon are at least several atoms big. It may be made of bunch of atoms of dopants, but they are embebed on a crystal dozens of atoms wide. Also, the wires ccertanly an't work without those dozens of atoms, and another wire can't be as close to share some of those atoms without being connected. For all practical porposes, the wire is dozens of atoms wide.
Why can't /. just anounce a semiconductor breakthrough for what it is? "Smaler wire made of silicon" would make it, for exemple.
And, by the way, Ohm's law holds at the atomic level as well as it holds for big conductors. People learned that by studying organic conductors ages ago. The problem is how to make silicon work the same way. That is what TFA seems to be about (don't really know because it is behind a pay wall).
Rethinking email
It sounds like they've created nano-scale insulated wire, kinda like myelin-coated nerve fibers.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
"which makes the conduction electrons more immune to outside influence" How can something be more or less immune than another?
The simple translation of this article is:
"We made really bad nanowires."
All that's necessary to demonstrate this effect is to create a system with enough defects and scattering (aka doping) to make scattering based resistance much larger than quantum resistance. This isn't something I thought was still under debate.
I hope we dont run out of phosphorus faster because of this!!
Google phosphorus shortage, plenty of hits.
Only for the specific structure they constructed. For most structure built at those dimensions Ohm's law does not survive. And you have to solve Schrödinger's equation to even estimate what the Ohm's law resistance is.