World’s smallest nanotube transistor

Researchers at the Munich laboratories of Infineon Technologies claim to have constructed the world’s smallest nanotube transistor.

Researchers at the Munich laboratories of Infineon Technologies claim to have constructed the world’s smallest nanotube transistor, with a channel length of only 18 nm – the most advanced transistors currently in production are almost four times this size.

To build their nanotransistor, the researchers grew carbon nanotubes, each one measuring only 0.7 to 1.1 nm in diameter, in a controlled process.

The nanotube transistor can deliver currents in excess of 15 µA at a supply voltage of only 0.4 V (0.7 V is currently the norm). A current density some 10 times above that of silicon, the material most commonly used today for the manufacture of transistors, has been observed.

Infineon says that the characteristic properties of carbon nanotubes make them the ideal candidate material for many applications in microelectronics: the tubes carry electrical current virtually without friction on their surface thanks to “ballistic” electron transport.

But the German researchers are just one of a number of groups that have built such transistors.

In April 2001, for example, IBM researchers built the world’s first array of transistors out of carbon nanotubes. And this year, that company went on to create an electrically-controlled light emitter based on a nanotube 1.4 nanometre in diameter that they configured as a three terminal transistor.

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