From the 4/1/11 issue of ACM Tech News:
The Incredible Shrinking Circuit
University of Cambridge (03/28/11)
University of Cambridge researchers have developed a technique for producing smaller microchips that can also support extremely high electrical current densities. Led by Cambridge professor John Robertson, the researchers used carbon nanotubes to replace the vertical copper connectors in integrated circuits to build smaller circuits and to reduce the size of electronics even further. They took advantage of the special arrangement of carbon atoms. Normally the atoms are arranged hexagonally and layered in sheets, but in nanotubes the sheets are rolled up to form tiny tubes with diameters equivalent to just a few carbon atoms. To make the approach feasible, the nanotubes would need to be grown in very dense bundles directly onto the substrate. Robertson and colleagues used multiple deposition and the annealing steps to grow nanotube bundles, and the method led to successive increases in nanoparticle density. The researchers say the density of the bundles is five times greater than current technology.