[ODCAD] Nanotube RAM could displace silicon memory
Balls, tubes, sheets ... carbon molecules have more contortions than Cirque du Soleil
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posted 2:47pm EST Mon May 12 2003 - submitted by J. Eric Smith
NEWS
Who says there's nothing worth watching on the tube these days? Nanotubes, that is. That funky carbon substance known economically as Buckminsterfullerene, a.k.a. "buckyballs," has been twisted and turned into a memory device that may revolutionize computer data storage as we know it.
Researchers at Massachusetts-based Nantero have arranged carbon molecules into tubes with a diameter around a billionth of a meter and only a few hundred nanometers long. By placing a few billion of these on a planar surface and applying an electric current, certain groups of tubes can be made to clump together. What's more, they stay clumped even after current is removed, being held together by Van der Waals forces. By applying a different current later the clumps can be made to separate, meaning that the clumps can function as a nanoscale storage device.
The huge advantage of Nantero's product is in density and speed: nanotubes can be switched from on to off in half a nanosecond, and billions of tubes can exist in a single square millimeter. Comparable silicon-based memory cells require tens of nanoseconds to operate and are currently 100 times the size of a single nanotube. Nanotubes even retain their contents after power is removed, something that conventional RAM does not, meaning that the technology could be used in place of mechanical hard drives.
You can read more about this fascinating development over at The Economist.
ERIC'S OPINION
I've seen the future, and it's really, really tiny. As I've mentioned in past articles, the ability to manipulate matter at molecular and atomic levels is not only going to be advantageous in the near future, it's going to be required to stay competitive. After that, quantum mechanics may offer similarly earthshattering leaps, but I suspect that's a bit further off.
It seems these neat carbon arrangements have become the Swiss Army knife of molecules. Buckyballs are being used to deliver drugs and treatments directly to cancer cells. Nanotubes are considered to be the first material that might make a space elevator possible, even practical. IBM's made transistors out of them.
There seems to be no limit, large or small, to what these little things can do.
Friday, June 25, 2004
[ODCAD] Nano conveyor of Metal
Source: Chemical Eng. News, May 3, 2004
Scientists from Univ. of Californian, Berkeley and Lawrence Berkeley National Lab have found a way to transport molten metal along nanotube.
Physics professor Alex Zettl, postdoc Christ Regan and their coworkers applied electrical current to a multiwalled carbon nanotube (MWNT), and the heat generated can melt contacting metal crystal. The metal then migrate along the tube from the anode to the cathode. The metal particles are shuttled along the surface of the nano tube in atomic form without evaporation. They observed that the metal can move over a greater distance than 2 um.
Potentially, this may be useful technology to make nano circuit or nano device combining metal with nano tube.
Copy right owned by OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Source: Chemical Eng. News, May 3, 2004
Scientists from Univ. of Californian, Berkeley and Lawrence Berkeley National Lab have found a way to transport molten metal along nanotube.
Physics professor Alex Zettl, postdoc Christ Regan and their coworkers applied electrical current to a multiwalled carbon nanotube (MWNT), and the heat generated can melt contacting metal crystal. The metal then migrate along the tube from the anode to the cathode. The metal particles are shuttled along the surface of the nano tube in atomic form without evaporation. They observed that the metal can move over a greater distance than 2 um.
Potentially, this may be useful technology to make nano circuit or nano device combining metal with nano tube.
Copy right owned by OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Tuesday, May 18, 2004
[ODCAD] Junction and Vacuum Level in Organic Devices
The electrical performance of a device is effected by the junctions present. The energy barrier is a major factor to consider in modeling the junction. In device physics, the vacuum level is regarded as the common reference point to calculate the energy barrier. In inorganic semiconductors based on Si material, it is always regarded as truth that the vacuum level is the same for all of contacting layers (materials). This is called Vacuum level alignment.
In organic devices, it is common that function layer is organic semiconductor, and electrode layers are inorganic materials. Scientists found that this vacuum level alignment may not be applicable in the junction between organic layer and inorganic layer. For example, the junctions Ag/Alq3, Ag/Almq3 have been observed that the vacuum levels are not aligned for difference about 1.1 eV [1].
This non aligned vacuum level can happen for system with or without chemical bond, and doped and undoped. It means that it is not due to chemical reaction in the junction. Scientists explained that there is dipole behaving like internal field across the junction. The source of the dipole is due to significant difference between two materials. The molecules in the junction try to arrange their position to have minimum free energy of the whole system. This junction and the dipole are different from p-n or Schottky junction in terms of size and field. They will be discussed in the other topic.
The consequence of different vacuum levels is critical for the energy barrier. For example, the vacuum level of organic layer is usually reduced by a amount (say 0.5 eV). For hole injection from the junction into the organic layer, the energy barrier is increased by that amount, while the energy barrier is reduced by that amount for electron injection. That amount of energy barrier change can result in significant effect to electrical performance of the device.
1. I. G. Hill, Appl. Phys., Vol. 84, 3236 (1998)
Copy right owned by OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
The electrical performance of a device is effected by the junctions present. The energy barrier is a major factor to consider in modeling the junction. In device physics, the vacuum level is regarded as the common reference point to calculate the energy barrier. In inorganic semiconductors based on Si material, it is always regarded as truth that the vacuum level is the same for all of contacting layers (materials). This is called Vacuum level alignment.
In organic devices, it is common that function layer is organic semiconductor, and electrode layers are inorganic materials. Scientists found that this vacuum level alignment may not be applicable in the junction between organic layer and inorganic layer. For example, the junctions Ag/Alq3, Ag/Almq3 have been observed that the vacuum levels are not aligned for difference about 1.1 eV [1].
This non aligned vacuum level can happen for system with or without chemical bond, and doped and undoped. It means that it is not due to chemical reaction in the junction. Scientists explained that there is dipole behaving like internal field across the junction. The source of the dipole is due to significant difference between two materials. The molecules in the junction try to arrange their position to have minimum free energy of the whole system. This junction and the dipole are different from p-n or Schottky junction in terms of size and field. They will be discussed in the other topic.
The consequence of different vacuum levels is critical for the energy barrier. For example, the vacuum level of organic layer is usually reduced by a amount (say 0.5 eV). For hole injection from the junction into the organic layer, the energy barrier is increased by that amount, while the energy barrier is reduced by that amount for electron injection. That amount of energy barrier change can result in significant effect to electrical performance of the device.
1. I. G. Hill, Appl. Phys., Vol. 84, 3236 (1998)
Copy right owned by OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Monday, May 17, 2004
[ODCAD] US Defence Dept.- Organic Photovotaics (PV)
Effective solar cell device definitly has great application in any electronic products that require power supply. Inorganic semiconductors like Si currently rule the market. Organic materials potentially have advantage of smaller size (thinner), light weight, effcient, flexible (bend without breaking), and low cost. Many experts, and labs bet the future of photovotaics (PV) on organic materials.
US Dept. of Defence may be the biggest investor in this technology. Lynne Samuelson, a researcher at the US Army's Natick Soldier Center, in Massachusetts, claimed that his lab is starting to make proto-type PV devices to try out in the field. That Lab teamed up with a chemistry lab at Univ. of Massachusetts Lowell. The structure and materials used in their cell may contain Titania (? it may mean Ti)-TiO2 particles/Polymer. Titania particle can be as small as 20nm. The polymer is polyethylene terephthalate. Its effciency has not been disclosed. It is estimated that it may be >4%. This lab is expecting 20% effciency in five years.
Some Information is from Spectrum of IEEE.
ODCAD from OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Effective solar cell device definitly has great application in any electronic products that require power supply. Inorganic semiconductors like Si currently rule the market. Organic materials potentially have advantage of smaller size (thinner), light weight, effcient, flexible (bend without breaking), and low cost. Many experts, and labs bet the future of photovotaics (PV) on organic materials.
US Dept. of Defence may be the biggest investor in this technology. Lynne Samuelson, a researcher at the US Army's Natick Soldier Center, in Massachusetts, claimed that his lab is starting to make proto-type PV devices to try out in the field. That Lab teamed up with a chemistry lab at Univ. of Massachusetts Lowell. The structure and materials used in their cell may contain Titania (? it may mean Ti)-TiO2 particles/Polymer. Titania particle can be as small as 20nm. The polymer is polyethylene terephthalate. Its effciency has not been disclosed. It is estimated that it may be >4%. This lab is expecting 20% effciency in five years.
Some Information is from Spectrum of IEEE.
ODCAD from OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Thursday, May 13, 2004
[ODCAD] Nano conveyor of Metal
Source: Chemical Eng. News, May 3, 2004
Scientists from Univ. of Californian, Berkeley and Lawrence Berkeley National Lab have found a way to transport molten metal along nanotube.
Physics professor Alex Zettl, postdoc Christ Regan and their coworkers applied electrical current to a multiwalled carbon nanotube (MWNT), and the heat generated can melt contacting metal crystal. The metal then migrate along the tube from the anode to the cathode. The metal particles are shuttled along the surface of the nano tube in atomic form without evaporation. They observed that the metal can move over a greater distance than 2 um.
Potentially, this may be useful technology to make nano circuit or nano device combining metal with nano tube.
Source: Chemical Eng. News, May 3, 2004
Scientists from Univ. of Californian, Berkeley and Lawrence Berkeley National Lab have found a way to transport molten metal along nanotube.
Physics professor Alex Zettl, postdoc Christ Regan and their coworkers applied electrical current to a multiwalled carbon nanotube (MWNT), and the heat generated can melt contacting metal crystal. The metal then migrate along the tube from the anode to the cathode. The metal particles are shuttled along the surface of the nano tube in atomic form without evaporation. They observed that the metal can move over a greater distance than 2 um.
Potentially, this may be useful technology to make nano circuit or nano device combining metal with nano tube.
Tuesday, April 27, 2004
[ODCAD] IBM: Nanotube Transistor, outperformed Si technology
Carbon nanotube can be used for many device application because of
its special electronic properties such as high electron mobility. IBM
developed a transistor based on C6 nanotube with the same drain,
source, gate and dielectric as Si CMOS technology, but using C6
nanotube instead of Si based semiconductor. The transistor has much
better performance than conventional one such as CMOS.
http://www.research.ibm.com/resources/news/20020520_nanotubes.shtml
For IBM, and all of the industry, they still have manufacture
difficulties to massive produce the device.
ODCAD from OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Carbon nanotube can be used for many device application because of
its special electronic properties such as high electron mobility. IBM
developed a transistor based on C6 nanotube with the same drain,
source, gate and dielectric as Si CMOS technology, but using C6
nanotube instead of Si based semiconductor. The transistor has much
better performance than conventional one such as CMOS.
http://www.research.ibm.com/resources/news/20020520_nanotubes.shtml
For IBM, and all of the industry, they still have manufacture
difficulties to massive produce the device.
ODCAD from OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Tuesday, April 20, 2004
[ODCAD] Nanofabrication :Imprint Technology of Organic Material
Conventional lithography technology limits its scaling capability by the wave length of light used. The nanotechnology requires line size 100nm or less. The UV light is being pushed to its limit for the task.
One approach is to use short wave length light such as x ray to replace current UV light. This may allow quality small size device production. However, this type of light usually is not time efficient because it can not penetrate very deep of the material resulting a long time production.
However, if it is just making a mold with short wave length light, it is fine because the mold can be reused many times in wafer process for small size device.
A mold can be made from a hard material, and not easily wearable. A desirable pattern can be made with short wave length light. After it is made, it can be used as a stamp.
Organic material such as polymer is usually soft. It can be stamped by a mold. In this way, a desired pattern can be made. This is imprinting technology. It is simple, cheap, and fast. Currently, HP uses this technology in high density organic memory fabrication. The pitch is in the range 40 nm (could be less).
ODCAD from OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Conventional lithography technology limits its scaling capability by the wave length of light used. The nanotechnology requires line size 100nm or less. The UV light is being pushed to its limit for the task.
One approach is to use short wave length light such as x ray to replace current UV light. This may allow quality small size device production. However, this type of light usually is not time efficient because it can not penetrate very deep of the material resulting a long time production.
However, if it is just making a mold with short wave length light, it is fine because the mold can be reused many times in wafer process for small size device.
A mold can be made from a hard material, and not easily wearable. A desirable pattern can be made with short wave length light. After it is made, it can be used as a stamp.
Organic material such as polymer is usually soft. It can be stamped by a mold. In this way, a desired pattern can be made. This is imprinting technology. It is simple, cheap, and fast. Currently, HP uses this technology in high density organic memory fabrication. The pitch is in the range 40 nm (could be less).
ODCAD from OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
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