IBM sees carbon nanotube breakthrough

April 27, 2001 —

IBM researchers reported Friday they have made a breakthrough in transistor technology
by building what they claim is the first array of transistors made out of carbon
nanotubes.

The researchers believe the breakthrough to be critical in that they have found
a material that can be used to make computer chips when silicon-based chips
can not be made any smaller. This is a problem chip makers will have to cope
with in the next 10 to 20 years, according to IBM officials.

According to Moore's Law, a principle laid down by Gordon Moore, one of the
guiding forces behind Intel, the number of transistors that can be crammed onto
a chip doubles every 18 months. But in the next 10 to 20 years some believe
silicon will reach its physical limits and will no longer be able to include
more transistors.

"We see this as a major step forward in our pursuit to build molecular
scale electronic devices," said Phaedon Avouris, lead researchers on the
project. "I think our studies prove that carbon nanotubes can compete with
silicon in terms of performance," he said.

Carbon nanotubes are tiny cylinders of carbon atoms measuring 10 atoms across
and are 500 times smaller than today's silicon-based transistors and reportedly
1,000 times stronger than steel.

The breakthrough achieved by IBM scientists bypasses the tedious process of
having to manipulate nanotubes one at a time, or separate them from the more
useful electrical properties from bundles of nanotubes.

The electrical properties of carbon nanotubes are either metallic or semiconducting.
In the past the problem scientists had in using them as transistors was that
all synthetic methods of production yield a mix of metallic nanotubes that would
stick together, rendering them unusable, an IBM spokesperson explained.

IBM researchers overcame this problem with a "constructive destruction"
technique that allows them to produce only semiconducting nanotubes with the
electrical properties necessary to build chips, the spokesperson said.

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