Using Nanotubes in Computer Chips

Sep 10, 2009

(PhysOrg.com) -- MIT materials scientists have developed a new technique for growing carbon nanotubes that could replace the vertical wires in chips, permitting denser packing of circuits.

Researchers in the lab of MIT materials science professor Carl V. Thompson grew dense forests of crystalline carbon nanotubes on a metal surface at temperatures close to those characteristic of computer chip manufacturing. Unlike previous attempts to do the same thing, the researchers' technique relies entirely on processes already common in the .

The researchers also showed that the crucial step in their procedure was to preheat the hydrocarbon gas from which the nanotubes form, before exposing the metal surface to it.

The transistors in computer chips are traditionally connected by tiny copper wires. But as chip circuitry shrinks and the wires become thinner, their conductivity suffers and they become more likely to fail. A simple enough manufacturing process could enable carbon nanotubes to replace the vertical wires in chips, permitting denser packing of circuits.

In a , the researchers vaporized the metals tantalum and iron, which settled in layers on a silicon wafer. Then they placed the coated wafer at one end of a quartz tube, which was inserted into a furnace. At the wafer's end of the tube, the furnace temperature was 475 degrees C; but at the opposite end, the temperature varied. The researchers pumped ethylene gas into the tube from the end opposite the wafer. When the temperature at that end approached 800 degrees, the ethylene decomposed, and the iron on the wafer catalyzed the formation of carbon nanotubes.

The researchers are trying to determine whether different combinations of metals and hydrocarbon gases can lower the catalytic temperature even further and improve the quality of the nanotubes.

More information: "Low Temperature Synthesis of Vertically Aligned Carbon Nanotubes with Electrical Contact to Metallic Substrates Enabled by Thermal Decomposition of the Carbon Feedstock," Gilbert Nessim, Carl V. Thompson et al, Nano Letters, Aug. 31, 2009

Provided by Massachusetts Institute of Technology (news : web)

Explore further: Nanoparticle technology triples the production of biogas

add to favorites email to friend print save as pdf

Related Stories

Engineers show nanotube circuits can be made en masse

Jul 04, 2008

Most innovations don't go far unless there is a way to turn them into products that are manufacturable on a mass scale. That's why new research on carbon nanotubes, presented June 19 by a group of Stanford electrical engineers, ...

High Value Semiconducting Carbon Nanotubes

Jul 12, 2004

A simple technique has been developed for producing high value semiconducting carbon nanotubes from samples of single and multi walled carbon nanotubes. The Oxford Invention is a technique for purifying samp ...

Probing the inner secrets of multi-layer carbon nanotubes

Apr 18, 2007

Researchers at the University of Surrey have shown for the first time that knowing the structure of the surface layer of a multi-layer carbon nanotube is not enough to predict its electronic properties. The contribution of ...

Recommended for you

Nanoparticle technology triples the production of biogas

11 hours ago

Researchers of the Catalan Institute of Nanoscience and Nanotechnology (ICN2), a Severo Ochoa Centre of Excellence, and the Universitat Autònoma de Barcelona (UAB) have developed the new BiogàsPlus, a technology which allows ...

Research unlocks potential of super-compound

14 hours ago

Researchers at The University of Western Australia's have discovered that nano-sized fragments of graphene - sheets of pure carbon - can speed up the rate of chemical reactions.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

Thex1138
not rated yet Sep 11, 2009
Hopefully this will lead to multi-layered chips, 3D.
poi
not rated yet Sep 11, 2009
good prospects, hope they get further funding and for the chip manufacturers to take on it. otherwise, it's another long wait.
IanVand
not rated yet Sep 11, 2009
The problem with integrating carbon nanotube technology with the current silicon manufacturing technology is the temperature required to form carbon nanotubes. If combined, the heat from the carbon nanotube process would destroy the functionality of the silicon transistors (by spreading the dopants in the N and P regions of transistors).

The process described in this paper may still be too hot to intregrate with current technologies, but investigating other catalysts for lowering the heat of producing nanotubes is a foot in the right direction.