Phase-Change Memory-Towards a Storage-Class Memory

• Published in: IEEE transactions on electron devices Vol. 64; no. 11; pp. 4374 - 4385
• Main Authors: Fong, Scott W., Neumann, Christopher M., Wong, H.-S Philip
• Format: Journal Article
• Language: English
• Published: IEEE 01.11.2017
• Subjects: Nonvolatile memory; Optical switches; Phase change materials; Phase-change memory (PCM); Random access memory; reset energy; Resistance; Resistance heating; thermal conductivity; thermal design
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2017.2746342

Phase-change memory (PCM) has undergone significant academic and industrial research in the last 15 years. After much development, it is now poised to enter the market as a storage-class memory (SCM), with performance and cost between that of NAND flash and DRAM. In this paper, we review the history of phase-transforming chalcogenides leading up to our current understanding of PCM as either a storage-type SCM, with high-density and better than NAND flash endurance, write speeds, and retention, or a memory-type SCM, with fast read/write times to function as a nonvolatile DRAM. Several of the key findings from the community relating to device dimensional scaling, cell design, thermal engineering, material exploration, and storing multiple levels per cell will be discussed. These areas have dramatically impacted the course of development and understanding of PCM. We will highlight the performance gains attained and the future prospects, which will help drive PCM to be as ubiquitous as NAND flash in the upcoming decade.