Santa Clara, Calif. — Intel Corp. and Numonyx B.V. have announced a key breakthrough in the research of phase change memory (PCM). For the first time, researchers have demonstrated a 64-Mb test chip that enables the ability to stack, or place, multiple layers of PCM arrays within a single die.
PCM is a new non-volatile memory technology that combines many advantages of today’s various memory devices. 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, according to the researchers.
The achievements are a result of an ongoing joint research program between Numonyx and Intel that focus on multi-layered or stacked PCM cell arrays. Intel and Numonyx researchers are now able to demonstrate a vertically integrated memory cell — called PCMS (phase change memory and switch).
PCMS is comprised of one PCM element layered with a newly used Ovonic Threshold Switch (OTS) in a true cross point array. The ability to layer or stack arrays of PCMS provides the scalability to higher memory densities while maintaining the performance characteristics of PCM, a challenge that is becoming increasingly more difficult to maintain with traditional memory technologies, according to the companies.
Memory cells are built by stacking a storage element and a selector, with several cells creating memory arrays. Intel and Numonyx researchers were able to deploy a thin-film, two-terminal OTS as the selector, matching the physical and electrical properties for PCM scaling. With the compatibility of thin-film PCMS, multiple layers of cross point memory arrays are now possible. Once integrated together and embedded in a true cross point array, layered arrays are combined with CMOS circuits for decoding, sensing and logic functions.
More information about the memory cell, cross point array, experiment and results will be published in a joint paper, “A Stackable Cross Point Phase Change Memory,” which will be presented at the 2009 International Electron Devices Meeting in Baltimore, Md., on December 9.