As transistor scaling down process continues, leakage current from gate to channel due to quantum mechanical tunnelling of electrons will become more significant.
Instead of trying new ways of mantaining the functionality of transistor at infinitesimal scales, Dr.Craig Lent, a researcher at University of Notre Dame, proposed a device which functions better as its features(i.e, size etc) get reduced, opposed to that of the transistor.This emerging nanotechnology come with the name of Quantum-Dot Cellular Automata(QCA), which seems to be very promising.
For more informations, please link to the site below:
http://people.atips.ca/~walus/tutorials/QCATutorial.html
This site provides tutorials, interestings accounts on QCA by Konrad Walus.
Have a nice day!

As transistor scaling down process continues, leakage current from gate to channel due to quantum mechanical tunnelling of electrons will become more significant.
Instead of trying new ways of mantaining the functionality of transistor at infinitesimal scales, Dr.Craig Lent, a researcher at University of Notre Dame, proposed a device which functions better as its features(i.e, size etc) get reduced, opposed to that of the transistor.This emerging nanotechnology come with the name of Quantum-Dot Cellular Automata(QCA), which seems to be very promising.
For more informations, please link to the site below:
http://people.atips.ca/~walus/tutorials/QCATutorial.html
This site provides tutorials, interestings accounts on QCA by Konrad Walus.
Have a nice day!

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Jianrong,
welcome to nanotech group!!!!!

Jianrong,
welcome to nanotech group!!!!!

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Hi everybody,
This is a small account on nanotechnology and wish it is not boring....
Nanotechnology(specificallly molecular manufacturing)
are studies on methods of manufacturing materials at the molecular scale.
Casting, grinding, milling and lithography are common, well known ways of shifting and placing atoms individually in the desired positions and merging these atoms into usually complex rather idiosyncratic patterns.
Characteristic dimensions in this field are typically less than 1000 nanometers.
Main objectives of nanotech:
1. Getting every atom in the desired positions.
2. Making most part of the structure built consistent with laws of physics, typically, quantum mechanics.
3. Meet low costs requirements given the raw materials available and energy required.

2 important concepts in nanotech:
Positional assembly which is manipulating and positioning individual atoms and molecules.This gave rise to molecular robotics which involves molecular scale positional devices likely to resemble macroscopic devices used in daily life.
Self replication/ self replicating manufacturing systems used to duplicate themselves as well as by-products in order to meet low cost consumption.

thank you for taking the trouble to read this simple account.
thank you Benedict for starting this group.....
Anyone feel free to share new developments in nanotech in their respective countries or places.

sincerely,

Hi everybody,
This is a small account on nanotechnology and wish it is not boring....
Nanotechnology(specificallly molecular manufacturing)
are studies on methods of manufacturing materials at the molecular scale.
Casting, grinding, milling and lithography are common, well known ways of shifting and placing atoms individually in the desired positions and merging these atoms into usually complex rather idiosyncratic patterns.
Characteristic dimensions in this field are typically less than 1000 nanometers.
Main objectives of nanotech:
1. Getting every atom in the desired positions.
2. Making most part of the structure built consistent with laws of physics, typically, quantum mechanics.
3. Meet low costs requirements given the raw materials available and energy required.

2 important concepts in nanotech:
Positional assembly which is manipulating and positioning individual atoms and molecules.This gave rise to molecular robotics which involves molecular scale positional devices likely to resemble macroscopic devices used in daily life.
Self replication/ self replicating manufacturing systems used to duplicate themselves as well as by-products in order to meet low cost consumption.

thank you for taking the trouble to read this simple account.
thank you Benedict for starting this group.....
Anyone feel free to share new developments in nanotech in their respective countries or places.

sincerely,

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No problem... I wish there are more people come to join us.

No problem... I wish there are more people come to join us.

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Below are some notes taken from an article in the magazine, Scientific American, by G.Dan Hutcheson:

Semiconductor manufacture is indeed real nanotechnology.The first transistor gates with dimensions less than 100 nanometers was produced in 2000.Integrated circuits emerging in the market now have gates a scant 50 nanometers wide.That's equivalent to 50 billionths of a meter, almost about a thousands the width of a human hair.
Saving space per se is not the impetus behind the push for extreme miniaturization but rather to lower the unit cost for each transistor.
The fundamental building block of a microprocessor is the field effect transistor(FET) , which is well known to every engineering students I supposed.This element acts as a simple switch.The proper voltage applied to the gate electrode induces charge along the channel, which then carries current between the source and the drain, turning the switch(ie. FET) ON(ie. active state).With sufficiently small gates, these transistors can switch ON and OFF billions of times each second.

to be continued......

Page 1

Below are some notes taken from an article in the magazine, Scientific American, by G.Dan Hutcheson:

Semiconductor manufacture is indeed real nanotechnology.The first transistor gates with dimensions less than 100 nanometers was produced in 2000.Integrated circuits emerging in the market now have gates a scant 50 nanometers wide.That's equivalent to 50 billionths of a meter, almost about a thousands the width of a human hair.
Saving space per se is not the impetus behind the push for extreme miniaturization but rather to lower the unit cost for each transistor.
The fundamental building block of a microprocessor is the field effect transistor(FET) , which is well known to every engineering students I supposed.This element acts as a simple switch.The proper voltage applied to the gate electrode induces charge along the channel, which then carries current between the source and the drain, turning the switch(ie. FET) ON(ie. active state).With sufficiently small gates, these transistors can switch ON and OFF billions of times each second.

to be continued......

Page 1

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Now come to the basic chip-making process:
A circular wafer of silicon about the size of a dinner plate povides the starting point for basic chip-making, which basically sculpts transistor and their interconnections.
Steps: 1. Surface of wafer is oxidized using steam.
2. Oxidized wafer is then coated with photoresist.
3. Lithography is employed to tranfer desired pattern from mask to wafer.
4. Chemicals and baking harden unexposed photoresist. while other parts of photoresist are removed.
5. Chemical etching selectively strips off the oxide where no photoresist protects it.The rest of photoresist is removed.
6.Ions shower etched areas, forming source and drain junctions.
7. Metal contacts are added using lithography during later stages of fabrication.

Now come to the basic chip-making process:
A circular wafer of silicon about the size of a dinner plate povides the starting point for basic chip-making, which basically sculpts transistor and their interconnections.
Steps: 1. Surface of wafer is oxidized using steam.
2. Oxidized wafer is then coated with photoresist.
3. Lithography is employed to tranfer desired pattern from mask to wafer.
4. Chemicals and baking harden unexposed photoresist. while other parts of photoresist are removed.
5. Chemical etching selectively strips off the oxide where no photoresist protects it.The rest of photoresist is removed.
6.Ions shower etched areas, forming source and drain junctions.
7. Metal contacts are added using lithography during later stages of fabrication.

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Following up is about the refinement in chip-making.
1. Performance has improved with the growing use of wafers having a buried oxide layer or those fashioned to have a thin layer of strained silicon at the top---or by employing both techniques at once.
2. If modern techniques such as " optical proximity correction" are applied to compensate for blurring effects of diffraction, photolithography can create features smaller than the wavelength of light used in projecting the pattern.
3. As feature sizes gets smaller and smaller, removing the photoresist. and residues that remain after etching becomes difficult.But supercritical carbon dioxide can penetrate tiny openings and dislodge particles without leaving traces of cleaning fluid behind.
4. As many as eight levels of wiring now connect the millions of transistors to and on a typical microprocessor.Aluminium, the metal long used for this purpose, has given way to copper, which is more difficult to emplace but improves speed and integrity of the signals carried on the wires.

How is it by slicing a nanochip?: G . Dan Hutcheson presents us the steps below:
1 silicon - on - insulator technology, which has helped improve chip performance considerably, has become cheaper and easier to adopt, thanks to a technique called Smart Cut, developed by Soitec, a French company.
2. Process begins with two silicon wafers, A and B.
3. Heat and steam oxidize the surface of wafer A.
4. Hydrogen ions penetrate the surface and slightly weaken a layer of silicon under the oxide. The wafer is then turned over.
5. After cleaning , the top of the wafer A is bonded to wafer B.
6.Wafer is split along the weakened layer, and the top is removed.
7. Heating and polishing finish the wafer processing.

Have a nice day, guys!
Wish you will enjoy!

Following up is about the refinement in chip-making.
1. Performance has improved with the growing use of wafers having a buried oxide layer or those fashioned to have a thin layer of strained silicon at the top---or by employing both techniques at once.
2. If modern techniques such as " optical proximity correction" are applied to compensate for blurring effects of diffraction, photolithography can create features smaller than the wavelength of light used in projecting the pattern.
3. As feature sizes gets smaller and smaller, removing the photoresist. and residues that remain after etching becomes difficult.But supercritical carbon dioxide can penetrate tiny openings and dislodge particles without leaving traces of cleaning fluid behind.
4. As many as eight levels of wiring now connect the millions of transistors to and on a typical microprocessor.Aluminium, the metal long used for this purpose, has given way to copper, which is more difficult to emplace but improves speed and integrity of the signals carried on the wires.

How is it by slicing a nanochip?: G . Dan Hutcheson presents us the steps below:
1 silicon - on - insulator technology, which has helped improve chip performance considerably, has become cheaper and easier to adopt, thanks to a technique called Smart Cut, developed by Soitec, a French company.
2. Process begins with two silicon wafers, A and B.
3. Heat and steam oxidize the surface of wafer A.
4. Hydrogen ions penetrate the surface and slightly weaken a layer of silicon under the oxide. The wafer is then turned over.
5. After cleaning , the top of the wafer A is bonded to wafer B.
6.Wafer is split along the weakened layer, and the top is removed.
7. Heating and polishing finish the wafer processing.

Have a nice day, guys!
Wish you will enjoy!

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Is anybody on this message board actively involved in the nanotech industry? I am interested in starting a high tech company myself, but nanotech is very interesting and I am a Discover and Scientific American magazine subscriber as well. I have a group called high tech start up that has some resources on there if anybody is interested.

Is anybody on this message board actively involved in the nanotech industry? I am interested in starting a high tech company myself, but nanotech is very interesting and I am a Discover and Scientific American magazine subscriber as well. I have a group called high tech start up that has some resources on there if anybody is interested.

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Hey Karim,

I am working on semiconductor fabrication technology and I am very interested in nano-tech as well. If you have information to share, I will be interested. Thanks !

Hey Karim,

I am working on semiconductor fabrication technology and I am very interested in nano-tech as well. If you have information to share, I will be interested. Thanks !

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Hey Karim,

I am working on semiconductor fabrication technology and I am very interested in nano-tech as well. If you have information to share, I will be interested. Thanks !

Hey Karim,

I am working on semiconductor fabrication technology and I am very interested in nano-tech as well. If you have information to share, I will be interested. Thanks !

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