Apr 13, 2006
Fujitsu makes a big push in nanotechnology
Japanese IT and communications giant Fujitsu is investing considerable sums in nanotechnology research. At the Nanotech 2006 event in Tokyo, the company showed off its progress with a large exhibit. Liz Kalaugher spoke to Naoki Yokoyama, general manager of Fujitsu's nanotechnology research centre to find out more.
"Nanotechnology is not a dream but very practical," said Yokoyama. "Already it is used to make high-end computers, using 90 nm technology, with a gate length of 40 nm and dielectric films less than 2 nm thick." The technology is also in place in today's magnetic data storage systems and in quantum well lasers for optical communications. As for the future, Fujitsu has streamed research at its nanotechnology centre into three groups that work on carbon nanotubes, nanobio and photonic devices.
The carbon nanotubes group is focusing on electronics applications. For example, in December 2005 the team revealed it had developed the world's first heatsink based on carbon nanotubes for semiconductor chips. The heatsink can dissipate the large amounts of heat generated by high-frequency high-power amplifiers, with the nanotubes forming the bumps in a flip-chip structure. Fujitsu hopes to commercialize the devices within two years and to deploy the technology in base stations for next-generation mobile communications in about three years.
The nanotubes team is also developing carbon nanotube vias for large-scale integrated circuit (LSI) interconnects for 32 nm chips and beyond. Smaller dimension chips will have higher current densities, which means that electromigration is likely to destroy copper wiring. But carbon nanotubes can handle much higher current densities and they also have excellent thermal conductivity, which helps with removing heat generated by the transistor. Yokoyama is "very proud" of this technology, which he hopes to commercialize by 2012.
LSI interconnects are also the target application for Fujitsu's nanoclustering silica technology. The material, which contain holes roughly 1 nm in diameter, has a low dielectric constant. This helps decrease signal delay in devices with very short wiring lengths, which can otherwise increase capacitance and cause signal delay. The material should find a use in 65 nm and 45 nm circuits and be commercially available within around three years.
Over in the nanobio group, progress is underway on a protein chip that contains an artificial antibody attached to a nucleotide nanostructure. Fujitsu researchers are collaborating with Gerhard Abstreiter of the Technical University of Munich, Germany, on the device, which could have applications in healthcare.
In the nanophotonic devices group, the focus is on quantum information technology such as quantum cryptography and quantum computing. Collaborations are ongoing on quantum dot lasers with Yasuhiko Arakawa of the University of Tokyo and on quantum information with Artur Ekert at the University of Cambridge, UK.
Fujitsu is developing a quantum dot laser made of gallium arsenide, rather than the indium phosphide used in conventional quantum well lasers. While indium phosphide is pricey and only available in 2 inch wafers, gallium arsenide is cheaper and comes in 6 inch diameters. The quantum dot lasers also offer low dispersion and, unlike quantum well lasers, an optical output power that's independent of temperature. The company says it has produced the world's first room-temperature continuous-wave quantum dot laser operating at 1.3 µm. The device can perform at speeds of 10 Gbit/s and emit single photons. It s slated for commercialization in 2008 for use in communications and broadcasting.
Yokoyama believes that quantum information technology is an area of much promise. "It will be more than 10 or 20 years before we can produce a practical quantum computer," he said. "But quantum cryptography will have limited applications in 2007 and 2008."
Yokoyama is also excited about the development of optical amplifiers and optical switches based on quantum dots. Such switches could have applications in petaFLOPS computer systems. "A supercomputer has many, many wires under the floor, like spaghetti," he explained. "By using optical switches and different wavelengths in the same fibre we could simplify this."
But that's not all. Fujitsu is involved in many other areas of nanotechnology, including nanomaterials simulation software, double-walled carbon nanotubes, metal nanoparticles and tubes of nanocarbon filled with ferromagnetic metal – a technology that could have applications in drug delivery or magnetic separation of DNA and protein molecules. What's more, the company is looking for partners in these fields, so this could be your chance to get involved.
About the author
Liz Kalaugher is editor of nanotechweb.org.