SFB 917: Resistively Switching Chalcogenides for Future Electronics - Structure, Kinetics and Device Scalability (Nanoswitches)

Basic data for this project

Description

The demand for data storage and processing continues to increase exponentially. To cope with the in-creased burden on data storage and processing, changes in computing architecture and hardware are urgently needed. It is the goal of SFB 917 to employ nanoswitches to realize novel storage devices and new computing paradigms. In the second reporting period of SFB 917 significant advances have been made. In particular, we gained an in-depth understanding of the nanoscale redox-processes of VCM devices and could describe the switching kinetics over 14 orders of magnitude. These insights have helped us to switch VCM materials in less than 350 ps, while a superior PC material could be identified based on DFT calculations which switches with reduced power in less than 1 ns. Last but not least, we have identified a novel bonding mechanism in crystalline phase change materials, which differs significantly from the three main bonding mechanisms (ionic, metallic and covalent) discussed in textbooks. These insights have led to a novel map containing all four major bonding mechanisms. This implies that resistive switches with desirable properties can be tailored with this map. Hence, in the third funding period we can employ rational materials design to advance the microscopic understanding of resistive switching phenomena. We intend to employ such treasure maps to explore the limits of the application potential of VCMs and PCMs. Of particular relevance are the limits in switching speed, scalability and reliability, since these will define the range of applications that can be envisioned for this material class. We hence plan to employ several different concepts to produce nanosize switches and study their switching speed and reliability with the platform of analysis and characterization methods we have developed in the first two funding periods. We will study the physics of new, promising VCM variants and investigate the microscopic mechanisms which limit the reliability of corresponding cells. For both, VCM and PCM, we plan to explore the scalability limits based on the treasure maps which have been elaborated.