'Universal memory' race still on the starting block
Mark LaPedus, Dylan McGrath
EE Times
12/19/2008 6:12 PM
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Phase vs. Sonos
And not to be outdone, there's phase-change. This technology--sometimes called ovonic unified memory (OUM)--dates back to 1970, when it was announced by Energy Conversion Devices Inc.
OUM is one of many efforts based on phase-change technology, which received considerable attention at IEDM. The technology is based on the electrically induced phase change of chalcogenide materials, which have been difficult to manufacture reliably in volumes. Phase-change materials have both crystalline and noncrystalline states that can represent "0" or "1," and it's possible to toggle between them by applying a small reset current.
Numoynx B.V. claims that it has officially shipped its PCM device commercially this week. Numonyx has finally shipped phase-change memory products amid some delays, after introducing the device last year.
That device, codenamed ''Alverstone,'' is a 90-nm, 128-Mbit part. Going forward, Numonyx is skipping the 65-nm node for the next device and moving "as quickly as possible" to the 45-nm node.
Numonyx (Rolle, Switzerland) is the memory spin-off of Intel Corp. and STMicroelectronics Inc. STMicroelectronics holds about a 49 percent stake in Numonyx, Intel has 45 percent, and Francisco Partners owns 6 percent.
At IEDM, Samsung described a ''unified 7.5-nm dash-type confined cell for PCM. IBM also had a paper on the subject.
Others are developing rival technologies. At IEDM, Toshiba Corp. broke its own record. Last year, Toshiba claimed that it had developed a new double tunneling junction layer technology, enabling memory devices with densities of over 100 gigabits in the 10-nm node generation.
Recently, the company showed a 15-nm device. This year, it demonstrated 10- and 8-nm memory devices. All devices deployed a double tunnel layer, based on a Sonos (silicon oxide nitride oxide semiconductor) type device structure. Sonos is a memory structure that holds electrons in the nitride layer in the gate insulator.
Toshiba showed that a 10-nm gate length bulk-planar Sonos-type memory device retains 2.6 decades memory window for 10 years in less than 13- V w/e voltages.
An 8-nm device shows the same performance. The structure sandwiches a 1.1-nm silicon nanocrystals layer between the 1-nm thickness oxide films.
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eetimes.eu
Page 4 of a good article on flash memory trends.
Regards,
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