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

• Subject Area: Computer Science, Systems and Electrical Engineering ; Chemistry ; Materials Science and Engineering ; Physics
• Term: from 2011 to 2023
• Website: Homepage
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 167917811

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.

• DFG Programme: Collaborative Research Centres

Current projects

• T02 - Tailoring phase change materials to RF Switches for 5G and 6G Technology (Project Head Wuttig, Matthias )

Completed projects

• A01 - From structure-property correlations to tailor-made chalcogenide materials (Project Heads Dronskowski, Richard ;  Wuttig, Matthias )
• A02 - Correlation between the atomic structure and electronic states in resistively switching oxides (Project Heads Dittmann, Regina ;  Waser, Rainer )
• A03 - Scanning tunneling microscopy and angle-resolved photoelectron spectroscopy of phase change materials (Project Heads Liebmann, Marcus ;  Morgenstern, Markus )
• A04 - Local confinement of switching filaments in transition metal oxides in electrical, chemical, mechanical, and thermal gradients (Project Heads Bihlmayer, Gustav ;  Szot, Krzysztof )
• A05 - High-temperature, high-pressure properties of chalcogenides and low-valent transition-metal oxides (Project Heads Dronskowski, Richard ;  Friese, Karen )
• A06 - Resistive switching of amorphous, non-stoichiometric oxide films (Project Head Martin, Manfred )
• B01 - Fast transient electrical analysis of resistive switching phenomena (Project Heads Böttger, Ulrich ;  Menzel, Stephan ;  Salinga, Martin )
• B02 - Electrocoloration: The electroformation process made visible (Project Heads Roth, Georg ;  Waser, Rainer )
• B03 - Fundamentals of ion transport processes in resistive switching oxides (Project Heads De Souza, Ph.D., Roger ;  Hoffmann-Eifert, Susanne )
• B04 - Exploring the impact of bonding on switching kinetics (Project Heads Mazzarello, Riccardo ;  Wuttig, Matthias )
• B05 - Investigating the influence of defects on charge carrier properties in resistive switching with near-field optical microscopy and spectroscopy (Project Head Taubner, Thomas )
• B06 - Electronic structure and phase formation in resistive memory materials (Project Head Schneider, Claus Michael )
• B07 - Continuum modeling of phase formation (Project Heads Apel, Markus ;  Brener, Efim )
• B08 - Theory and modelling of valence change based resistive switching (Project Heads Blügel, Stefan ;  Jungemann, Christoph ;  Lezaic, Marjana )
• B09 - In situ transmission electron microscopy of resistive switching devices (Project Head Dunin-Borkowski, Rafal E. )
• B10 - Resistive switching mechanism in Mott oxide insulators (Project Head Wouters, Dirk )
• C01 - Size effects on the phase stability and switching properties of chemically synthesized HfO2 and Sb-based chalcogenide nanoparticles (Project Head Simon, Ulrich )
• C02 - Defect engineering and scaling of resistively switching oxide thin films (Project Head Dittmann, Regina )
• C03 - Self-assembled phase-change nanowires (Project Head Hardtdegen, Hilde )
• C04 - Effects of nanoscale confinement on the properties of phase change materials (Project Head Salinga, Martin )
• C06 - Growth, structure and switching of phase change materials in reduced dimensions (Project Heads Cojocaru-Mirédin, Ph.D., Oana ;  Wuttig, Matthias )
• C07 - Atomic scale imaging and manipulation of transition metal oxides (Project Head Karthäuser, Silvia )
• C08 - Study of localized defects in phase change materials and oxides with atom probe tomography and correlative microscopy (Project Head Cojocaru-Mirédin, Ph.D., Oana )
• MGK - Integrated Research Training Group (Project Heads Cojocaru-Mirédin, Ph.D., Oana ;  Mayer, Joachim )
• T01 - Failure mechanism and reliability of valence change memories (Project Head Waser, Rainer )
• Z01 - Integration and nanopatterning techniques (Project Heads Grützmacher, Detlev ;  Juschkin, Larissa )
• Z02 - Characterization of atomistic and electronic structures with ultra-high-resolution TEM (Project Head Mayer, Joachim )
• Z03 - Central Tasks (Project Head Wuttig, Matthias )
• Z04 - Nanoscale technology platform for ReRAM and PCM devices (Project Head Wouters, Dirk )
• Ö - NanoScienceOpen: Bringing nanoswitches to the public and the nature of science to pupils (Project Heads Detemple, Ralf ;  Heinke, Heidrun )

• Applicant Institution: Rheinisch-Westfälische Technische Hochschule Aachen
• Participating Institution: Forschungszentrum Jülich
• Spokesperson: Professor Dr. Matthias Wuttig