R&D: Interface Controlled Thermal Resistances of Ultra-Thin Chalcogenide-Based PCM

Nature Communications has published an article written by Kiumars Aryana, John T. Gaskins, Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, 22904, USA, Joyeeta Nag, Derek A. Stewart, Zhaoqiang Bai, Western Digital Corporation, San Jose, CA, 95119, USA, Saikat Mukhopadhyay, NRC Research Associate at Naval Research Laboratory, Washington, DC, 20375, USA, John C. Read, Western Digital Corporation, San Jose, CA, 95119, USA, David H. Olson, Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, 22904, USA, Eric R. Hoglund, James M. Howe, Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA, 22904, USA, Ashutosh Giri, Department of Mechanical, Industrial and Systems Engineering, University of Rhode Island, Kingston, RI, 02881, USA, Michael K. Grobis, Western Digital Corporation, San Jose, CA, 95119, USA, and Patrick E. Hopkins, Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, 22904, USA, Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA, 22904, USA, and Department of Physics, University of Virginia, Charlottesville, VA, 22904, USA.

Abstract: “Phase change memory (PCM) is a rapidly growing technology that not only offers advancements in storage-class memories but also enables in-memory data processing to overcome the von Neumann bottleneck. In PCMs, data storage is driven by thermal excitation. However, there is limited research regarding PCM thermal properties at length scales close to the memory cell dimensions. Our work presents a new paradigm to manage thermal transport in memory cells by manipulating the interfacial thermal resistance between the phase change unit and the electrodes without incorporating additional insulating layers. Experimental measurements show a substantial change in interfacial thermal resistance as GST transitions from cubic to hexagonal crystal structure, resulting in a factor of 4 reduction in the effective thermal conductivity. Simulations reveal that interfacial resistance between PCM and its adjacent layer can reduce the reset current for 20 and 120 nm diameter devices by up to ~?40% and ~?50%, respectively. These thermal insights present a new opportunity to reduce power and operating currents in PCMs.“