Junctionless transitors!

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Cogman

Lifer
Sep 19, 2000
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http://www.eetimes.com/223100050

All I can say is, wow, that would indeed be impressive if they could master this. Close to zero leakage, the ability to get MUCH smaller then normal transitors, higher switching speeds, and I wouldn't be surprised if they draw less power. And it silicon!

Yeah, we've seen promises like this before, and there is no telling what will happen with this, but it could be a decent breakthrough for CPU speed/power consumption.
 

TuxDave

Lifer
Oct 8, 2002
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I've been out of school too long but anyone want to give a pointer to "The gate can be used the squeeze the electron channel to nothing without the use of junctions or doping."
 

frostedflakes

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Mar 1, 2005
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Basically a field-effect transistor, but the construction is very different from traditional FETs. There's just a wire, then an insulating layer and conductive "ring" around it that's used to control the current in the wire.
 
May 11, 2008
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http://www.eetimes.com/223100050

All I can say is, wow, that would indeed be impressive if they could master this. Close to zero leakage, the ability to get MUCH smaller then normal transitors, higher switching speeds, and I wouldn't be surprised if they draw less power. And it silicon!

Yeah, we've seen promises like this before, and there is no telling what will happen with this, but it could be a decent breakthrough for CPU speed/power consumption.

That is very interesting. :)


The breakthrough is based on the deployment of a control gate around a silicon wire that measures just a few dozen atoms across. The gate can be used to "squeeze" the electron channel to nothing without the use of junctions.


Like most people i know the basic junction explanation but the text above i find interesting. To come back to the junction explanation, i read a few months ago an article where it seems that no one actually really knows how the junction works especially on a quantum mechanical level. When i read that article it read to me as basically making a transistor is just trial and error until the desired specifications are found when a certain border of complexity/Miniaturization has been crossed. I will try to find it again.

The original junction principle explanation was based on something from Charles-Augustin de Coulomb, if i am not mistaking.

http://en.wikipedia.org/wiki/Charles-Augustin_de_Coulomb

But if i would read the quoted text, by applying a voltage the researchers can change the configuration of the atom structure of the wire and by doing this reducing the amount of possible situations where electrons can freely move about in the wire ? This has perhaps also something to do with the valence band ?

http://en.wikipedia.org/wiki/Valence_band


EDIT: How big is the distance between the "gate" and the wire ?
If it is really small i would think that the electron clouds of the gate interact and interfere with the electrons (or possible electron locations where an electron can freely roam around) in the atom structure of the wire. Therefore controlling the amount of free electrons. Can that be the case ?
It reminds me for some reason of the quantum mirage and the super atoms. But then again , the big question is why is there no electron interaction (leakage) between the gate and the wire ?

http://en.wikipedia.org/wiki/Scanning_tunneling_microscope
 
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May 11, 2008
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That is very interesting. :)





Like most people i know the junction explanation but the text above i find interesting. To come back to the junction explanation, i read a few months ago an article where it seems that no one actually really knows how the junction works especially on a quantum mechanical level. When i read that article it read to me as basically making a transistor is just trial and error until the desired specifications are found when a certain border of complexity/Miniaturization has been crossed. I will try to find it again.

The original junction principle explanation was based on something from Charles-Augustin de Coulomb, if i am not mistaking.

http://en.wikipedia.org/wiki/Charles-Augustin_de_Coulomb

But if i would read the quoted text, by applying a voltage the researchers can change the configuration of the atom structure of the wire and by doing this reducing the amount of possible situations where electrons can freely move about in the wire ? This has perhaps also something to do with the valence band ?

http://en.wikipedia.org/wiki/Valence_band


EDIT: How big is the distance between the "gate" and the wire ?
If it is really small i would think that the electron clouds of the gate interact and interfere with the electrons (or possible electron locations where an electron can freely roam around) in the atom structure of the wire. Therefore controlling the amount of free electrons. Can that be the case ?
It reminds me for some reason of the quantum mirage and the super atoms. But then again , the big question is why is there no electron interaction (leakage) between the gate and the wire ?

http://en.wikipedia.org/wiki/Scanning_tunneling_microscope

Can it be based on delocalized electrons ?

http://en.wikipedia.org/wiki/Delocalized_electron
 

Cogman

Lifer
Sep 19, 2000
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Can it be based on delocalized electrons ?

http://en.wikipedia.org/wiki/Delocalized_electron

Semiconductors/conductors in general are based on the concept of delocalized electrons (or holes) My guess is that this is as well (considering it is using silicon and silicon substrates).

My guess is that by applying a voltage on the "wedding ring band" that this transistor somehow expands/contracts. Thus cutting off the flow of electrions. Since it was stated in the article that it could be arranged into a CMOS fashion, I'm going to guess that somehow the alternative is true (removing the voltage shuts the gate).

Detail are scarce, From the article you know as much as I do.

One possibility of how this works is that somehow the there is a collection of electrons on the ring. That collection creates a net negative charge which would disallow current to flow from one side to the other (you might have a collection of positive charges, but the charge carriers would generally create the gap needed to stop the flow). Once the electrons are removed from the ring, charge can flow, allowing for the change in voltages.
 
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May 11, 2008
22,551
1,471
126
Semiconductors/conductors in general are based on the concept of delocalized electrons (or holes) My guess is that this is as well (considering it is using silicon and silicon substrates).

My guess is that by applying a voltage on the "wedding ring band" that this transistor somehow expands/contracts. Thus cutting off the flow of electrions. Since it was stated in the article that it could be arranged into a CMOS fashion, I'm going to guess that somehow the alternative is true (removing the voltage shuts the gate).

Detail are scarce, From the article you know as much as I do.

One possibility of how this works is that somehow the there is a collection of electrons on the ring. That collection creates a net negative charge which would disallow current to flow from one side to the other (you might have a collection of positive charges, but the charge carriers would generally create the gap needed to stop the flow). Once the electrons are removed from the ring, charge can flow, allowing for the change in voltages.

I was not sure anymore, thank you for the confirmation. ^_^

EDIT:

A voltage is always supplied as reference to something. That can be the substrate, but that does not always have to be the case i guess.

That would possibly mean that a negative voltage must be applied to the ring with respect to the wire. I assume this transistor would work because of the Coulomb blockade.

http://en.wikipedia.org/wiki/Coulomb_blockade
 
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Brian Stirling

Diamond Member
Feb 7, 2010
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I've been out of school too long but anyone want to give a pointer to "The gate can be used the squeeze the electron channel to nothing without the use of junctions or doping."

My thoughts exactly ... the current flow through a bipolar transistor is directly controlled by the junctions but in a FET the current flows through a channel, not a junction. That there maybe a junction of sorts in some FET's isn't the point. All the current going through the load in a bipolar transistor must go through a junction, all of it. In a FET the current going through the load goes through the channel and not through a junction.


Brian
 
May 11, 2008
22,551
1,471
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My thoughts exactly ... the current flow through a bipolar transistor is directly controlled by the junctions but in a FET the current flows through a channel, not a junction. That there maybe a junction of sorts in some FET's isn't the point. All the current going through the load in a bipolar transistor must go through a junction, all of it. In a FET the current going through the load goes through the channel and not through a junction.


Brian

You are very right. I think they use the term junction because of this :
In classical mechanics the insulation between the gate and the channel can be seen as a barrier that can not be crossed. But what all the transistors manufacturers and especially the cpu designers on leading edge transistor technology encountered was that this barrier was more or less turning into a swiss cheese. The electron flow( or hole flow) through this barrier (insulation) became increasingly large. I think they talk of the junction when it comes to gate - insulation - channel. I may be wrong (please correct me) but that would be 2 junctions there.

http://en.wikipedia.org/wiki/P-n_junction
P-N junction may not be used, but they do seem to exist inside the Field Effect Transistor.
http://en.wikipedia.org/wiki/MOSFET

Every time i learn something new. :)
I always was curious about what is with the metal in a Metal Oxide Semiconductor Fet ?

The 'metal' in the name is now often a misnomer because the previously metal gate material is now often a layer of polysilicon (polycrystalline silicon). Aluminium had been the gate material until the mid 1970s, when polysilicon became dominant, due to its capability to form self-aligned gates. Metallic gates are regaining popularity, since it is difficult to increase the speed of operation of transistors without metal gates.

Kudos to Intel for going back to metal gates and solving various problems from polysilicon while also solving the problems encountered when making real mosfet's.
 
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