Intel Corp. and Numonyx B.V. announced a breakthrough in the development of phase-change memory (PCM) today that has the potential to allow developers to stack multiple layers of PCM arrays in a single die, thereby greatly increasing the density of the nonvolatile memory medium.
Calling the discovery a "milestone" in phase-change memory development, the researchers said they have so far only been able to build a single-layer, 64Mbit chip with the potential for other 64Mbit arrays to be stacked along with it.
Greg Atwood, a senior technology fellow at Numonyx, said the breakthrough in stackable PCM, which is being called PCM-stackable (PCMS), has the potential to create products that can replace DRAM, NOR and NAND flash memory because it will have better bandwidth, greater density and a cost per gigabyte of capacity comparable with today's solid state disk (SSD) drive products.
"We believe it enables the possibility of combining the functionality and performance of phase-change memory with more NAND-like cost structure," Atwood said. "And, it's of particular interest given the challenges the existing non-volatile memory technologies are facing over the next decade as well as the continued expansion of [PCM] usage."
The two companies have been working on development of PCM products since 2000, and a stackable PCM product since 2002. Al Fazio, an Intel fellow and director of memory technology development, said it's not unusual for a new memory type to take as many as 10 years to develop.
Atwood said that because the stacking breakthrough builds on top of PCM, a technology already in production, "it's a leading candidate amongst the various stackable memory concepts, most of which have no basis in a proven technology."
Other non-volatile memories in development include graphite memory, and race track memory.
Atwood added that Intel and Numonyx have no current time line for bringing PCMS products to market.
Phase-change memory is made up of a glass-like material called chalcogenide that can be switched between a crystalline and random state using low-voltage electricity.
Current NAND flash memory lithography technology resides at the 32-nanometer level. Future roadmaps scale NAND flash to 20 nanometers, but physical limitations present a barrier to creating anything more dense than that.
PCM, however, currently has the ability to scale to 5 nanometers in size, and the potential of even greater densities, Fazio said.