The technology of storing electronic information from old cassette tapes to shiny laptop computers has been a major force in the electronics industry for decades.
Low-power, high-efficiency electronic memory could be the long-term result of collaborative research led by Cornell materials scientist Darrell Schlom. The research, to be published April 17 in the journal Science (Vol. 324 No. 5925), involves taking a well-known oxide, strontium titanate, and depositing it on silicon in such a way that the silicon squeezes it into a special state called ferroelectric a result that could prove key to next-generation memory devices.
Ferroelectric materials are found today in "smart cards" used in many subways and ski resorts. The credit card-sized devices are made with such materials as lead zirconium titanate or strontium bismuth tantalate, which can instantly switch between different memory states using very little electric power. A tiny microwave antenna inside the card, when waved before a reader, reveals and updates stored information.
For more than half a century, scientists have wanted to use ferroelectric materials in transistors, which could lead to "instant-on" computing no more rebooting the operating system or accessing memory slowly from the hard drive. No one has yet achieved a ferroelectric transistor that works.
"Adding new functionality to transistors can lead to improved computing and devices that are lower power, higher speed and more convenient to use," said Schlom, professor of materials science and engineering. "Several hybrid transistors have been proposed specifically with ferroelectrics in mind. By creating a ferroelectric directly on silicon, we are bringing this possibility closer to realization."
Ordinarily, strontium titanate in its relaxed state is not ferroelectric at any temperature. The researchers have demonstrated, however, that extremely thin films of the oxide just a few atoms
|Contact: Blaine Friedlander|