In January, Intel announced that it can further shrink the size of a transistor by replacing oxidized silicon with the metal hafnium in its insulating layer. The insulator regulates the flow of current between a source and sink of electrons and therefore helps to govern how quickly a transistor can switch on or off: the thinner the insulator, the faster the switch. In addition, the tinier the transistor, the more that can fit onto a chip. But as silicon-based insulators have shrunk, they have leaked charge, forcing chips to consume much more power to run. Hafnium has superior insulating properties at such small scales, making it less “leaky” than silicon. With this metal, Intel expects to shrink the smallest dimension of its transistors from today's 65 nanometers to a svelte 45 nanometers, keeping the furious pace of transistor miniaturization on its expected track. IBM says it plans to release a similarly modified transistor next year.
This article was originally published with the title "Shrinking by Hafnium" in Scientific American 296, 4, 28 (April 2007)