Intel and Numonyx say they have achieved a research milestone in computer memory that could one day lead to a less expensive and higher-performing alternative to the technology used today.
The accomplishment stems from the work the two companies have been doing together on a type of non-volatile memory called phase-change memory, or PCM. The research partners say they have successfully stacked multiple layers of PCM arrays within a single 64 Mb die.
In demonstrating a verticially integrated memory cell comprising PCM and an ovonic threshold switch, researchers have shown that its possible to use the technologies to build chips that cost less and have higher performance and memory densities than traditional NAND flash memory used in a variety of applications, such as system memory in computers and handheld devices and solid-state drives used as an alternative to hard drives in PCs and servers.
The expense and storage limitations of today's solid-state drives have been a roadblock to broader use of the technology in data centers, even though SSDs are faster and more reliable than hard drives.
The reason PCM could prove a better alternative to NAND is because the former uses far less voltage. Where NAND uses an electrical charge to store and read memory, PCM uses heat on chalcogenide glass, which is the same material used in re-writable optical media, such as CDs and DVDs.
Using less voltage means PCM can store much more memory in a single die while using far less power. That's because NAND's use of electrical charges makes it difficult to scale the memory down to less than 20 nanometers and remain stable. PCM, on the other hand, can scale down to less than 5 nm.
However, while PCM's reliance on the temperature sensitivity of chalcogenide glass has major advantages, it is also the memory type's most notable drawback. Switching to PCM may require major changes to the production process of manufacturers, which could prove difficult in taking the technology from the lab to the commercial world. Intel's and Numonyx's' latest accomplishment is strictly a research milestone, not a production or commercial one.
Nevertheless, researchers say the progress in PCM is encouraging.
"The results are extremely promising," Greg Atwood, senior technology fellow at Numonyx, said in a statement released Wednesday. "The results show the potential for higher density, scalable arrays and NAND-like usage models for PCM products in the future.
"This is important as traditional flash memory technologies face certain physical limits and reliability issues, yet demand for memory continues to rise in everything from mobile phones to data centers."
Intel and Numonyx plan to present a paper on their achievement at the International Electron Devices Meeting in Baltimore, Md, Dec. 9.
Intel and STMicroelectronics last year presented a paper describing a high-density, multi-level cell memory device using PCM technology. Moving from a single bit per cell to a MLC significantly increased the density of the memory type. The paper was presented at the International Solid State Circuits Conference in San Francisco.
Numonyx is a joint venture formed last year by Intel, STMicroelectronics and private equity firm Francisco Partners. The company was formed to absorbed the tech companies' money-losing flash memory businesses for memory devices.
When formed, Numonyx was expected to generate $3.6 billion in annual revenue, mostly from flash memory products for consumers and industry. Its assets included research and development, manufacturing, and sales and marketing from Intel and STMicroelectronics.
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