Avalanche‐Discharge‐Induced Electrical Forming in Tantalum Oxide‐Based Metal–Insulator–Metal Structures |
| |
| Authors: | Katharina Skaja Christoph Bäumer Oliver Peters Stephan Menzel Marco Moors Hongchu Du Manuel Bornhöfft Christoph Schmitz Vitaliy Feyer Chun‐Lin Jia Claus Michael Schneider Joachim Mayer Rainer Waser Regina Dittmann |
| |
| Affiliation: | 1. Peter Grünberg Institut, Forschungszentrum Jülich, Jülich, Germany;2. Ernst Ruska‐Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich, Germany;3. Central Facility for Electron Microscopy, RWTH Aachen University, Aachen, Germany;4. Faculty of Physics, University of Duisburg, Duisburg, Germany;5. Institute of Materials in Electrical Engineering and Information Technology II, RWTH Aachen University, Aachen, Germany |
| |
| Abstract: | Oxide‐based metal–insulator–metal structures are of special interest for future resistive random‐access memories. In such cells, redox processes on the nanoscale occur during resistive switching, which are initiated by the reversible movement of native donors, such as oxygen vacancies. The formation of these filaments is mainly attributed to an enhanced oxygen diffusion due to Joule heating in an electric field or due to electrical breakdown. Here, the development of a dendrite‐like structure, which is induced by an avalanche discharge between the top electrode and the Ta2O5‐x layer, is presented, which occurs instead of a local breakdown between top and bottom electrode. The dendrite‐like structure evolves primarily at structures with a pronounced interface adsorbate layer. Furthermore, local conductive atomic force microscopy reveals that the entire dendrite region becomes conductive. Via spectromicroscopy it is demonstrated that the subsequent switching is caused by a valence change between Ta4+ and Ta5+, which takes place over the entire former Pt/Ta2O5‐x interface of the dendrite‐like structure. |
| |
| Keywords: | forming PEEM reduction resistive switching |
|
|
