Faster and More Energy Efficient Memories


RWTH researchers publish their latest results in the scientific journal Science Advances


Phase-change materials, PCMs for short, are one of the most promising candidates for future memory technologies. The materials can be reversibly switched between the amorphous and crystalline states. Since the phase transformation is also accompanied by a pronounced change in optical and electrical properties, these materials have recently been introduced in a commercial non-volatile memory, Intel and Micron’s OPTANE memory.

This memory is already about a hundred times faster than currently available Flash memories. The increasing importance of artificial intelligence methods and the associated desire to analyze ever larger data sets, in conjunction with the need to reduce worldwide energy consumption, place great demands on devices for electronic data storage. It is therefore imperative to further increase their operating speed and reduce their energy consumption.

At RWTH, research on this topic is currently being conducted as part of the Collaborative Research Center “Nanoswitches: Resistively Switching Chalcogenides for Future Electronic Applications – Structure, Kinetics, and Device Scalability“ (SFB 917).

Researchers at RWTH Aachen University, headed by Professor Matthias Wuttig, Chair of Experimental Physics I A and co-director of the JARA Institute for Energy-Efficient Information Technology (Green IT), and Dr. Shuai Wei, Chair of Experimental Physics I A, now present a possible solution to this problem in collaboration with Huazhong University of Science and Technology in China.

They discovered a physical phenomenon called β relaxation in the phase-change materials and found that some atoms in certain regions move much faster than the average atomic speed. "The observation of a fast local atomic motion in amorphous phase-change materials is interesting and unexpected, since such a process does not exist in conventional covalent glasses," explains Wei. “Amorphous phase-change materials apparently belong to an unconventional kind of covalent glasses.”

These fast atoms can facilitate the crystallization process and increase the switching speed in computer memory devices. The understanding of the new physical phenomenon offers opportunities for the modification of local motions at the atomic level, which in turn can be used to control the switching kinetics in phase-change memories and to reduce energy consumption. The researchers have published their results in the scientific journal "Science Advances".

RWTH Innovation GmbH is now supporting the research team in exploiting the technological potential and filing a patent for a new device concept in phase-change memories.