Monday, September 12, 2005

"CHIPS: Conductive diamond/nanotubes promise ice chips"

Argonne National Laboratories has found a way to make diamond a conductor as well as an insulator and semiconductor, opening the door to a new era of all-diamond chips. A spin-off company, Advanced Diamond Technologies Inc., has licensed the technology and material for development. In general, diamond deposition yields high-performance, long-lasting, radiation-hard dielectric films that can be thin or thick, can be etched alongside silicon components and can be doped either as n- or p-type semiconductors. Diamond's stiffness yields faster resonators, its smoothness yields friction-free microelectromechanical systems and its chemical inertness makes it ideal for bioengineered devices such as human implants. Argonne's patented ultrananocrystalline-diamond deposition taps a plasma-enhanced chemical-vapor process that is seeded with 2- to 5-nanometer grains of diamond. Instead of growing layers of single-crystal diamond one atom at a time, Argonne's process grows the material from seeds to islands to film. By adjusting the ultrananocrystalline process, the lab's researchers have managed to grow nanotubes between the diamond islands, turning what would ordinarily be a dielectric that insulates as well as silicon dioxide into a conductor that conducts as well as aluminum or copper.