Phase change memory is another step closer

Intel and Numonyx hit stackable milestone.

Intel and Numonyx have announced a research milestone in the development of stackable, cross-point phase change memory (PCM) technology, which could fundamentally alter the non-volatile memory market in years to come.

PCM uses chalcogenide glass and the application of heat to change states between crystalline and amorphous. In this case, the researchers have developed a way to make both the selector and storage elements based on chalcogenide materials and from that are able to create a vertically integrated memory cell comprised of one PCM element layered with a newly used Ovonic Threshold Switch (OTS) in a true cross point array.

According to Al Fazio, Intel Fellow and director of memory technology development the ability to stack these arrays allows for a level of scalability needed for mass market adoption.

Researchers from Chipzilla and the memory maker have jointly demonstrated a 64Mb test chip based on the new technology. The demo chip is just a single layer unit, but the design allows for the placing of multiple layers of PCM arrays within a single die.

If this type of memory can be cost-effectively scaled to usable memory sizes, it could potentially act as a sort of catch all storage, collapsing the need for separate NAND and DRAM memory components.

Fazio reckons that these findings pave the way for building memory devices with greater capacity, lower power consumption and optimal space savings for random access non-volatile memory and storage applications.

"The results are extremely promising," added Greg Atwood, senior technology fellow at Numonyx.

"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 centres."

Fazio and Atwood admit the technology still has a way to go and faces some stiff competition, from incumbent and other developing memory technologies, before it's ready for commercialisation, but both are excited by the prospects of this latest milestone.

More information about the memory cell will be delivered in a joint paper at the 2009 International Electron Devices Meeting taking place on 9 December in Baltimore.