Intel and Numonyx achieve stacking of PCM arrays to increase memory capacity

Intel and Numonyx have developed a 64Mb test chip by stacking multiple layers of PCM arrays within a single die so that the high memory capacity is achieved with in small footprint.

Through this, Intel and Numonyx researchers have demonstrated 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 cross point array. The ability to layer or stack arrays of PCMS provides the scalability to high memory densities while maintaining the performance characteristics of PCM, a challenge that is becoming more difficult to maintain with new memory technologies.

"We continue to develop the technology pipeline for memories in order to advance the computing platform," said Al Fazio, Intel Fellow and director, memory technology development. "We are encouraged by this research milestone and see future memory technologies, such as PCMS, as critical for extending the role of memory in computing solutions and in expanding the capabilities for performance and memory scaling."

"The results are extremely promising," said 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 centers."

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 cross point array, layered arrays are combined with CMOS circuits for decoding, sensing and logic functions.