Silicon oxide-based resistive switching devices show great potential for applications in nonvolatile random access memories. We expose a device to voltages above hard breakdown and show that hard oxide breakdown results in mixing of the SiOx layer and the TiN lower contact layers. We switch a similar device at sub-breakdown fields in situ in the transmission electron microscope (TEM) using a movable probe and study the diffusion mechanism that leads to resistance switching. By recording bright-field (BF) TEM movies while switching the device, we observe the creation of a filament that is correlated with a change in conductivity of the SiOx layer. We also examine a device prepared on a microfabricated chip and show that variations in electrostatic potential in the SiOx layer can be recorded using off-axis electron holography as the sample is switched in situ in the TEM. Taken together, the visualization of compositional changes in ex situ stressed samples and the simultaneous observation of BF TEM contrast variations, a conductivity increase, and a potential drop across the dielectric layer in in situ switched devices allow us to conclude that nucleation of the electroforming—switching process starts at the interface between the SiOx layer and the lower contact.
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Co-Editor-in-Chief: Pavel Hozak (for biomedical sciences)
Filippo Giannazzo - Consiglio Nazionale delle Ricerche (CNR), Institute for Microelectronics and Microsystems (IMM), Catania, Italy
Werner Grogger - FELMI, Graz University of Technology, Graz, Austria
János Lábár - Institute of Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, Budapest, Hungary
Erik Manders - Faculty of Science, SILS, University of Amsterdam, Amsterdam, The Netherlands
Ohad Medalia - Department of Biochemistry, Zürich University, Zürich, Switzerland
Rainer Pepperkok - EMBL, Heidelberg, Germany
Aleksander Recnik - J. Stefan Institute, Ljubljana, Slovenia
Sara Sandin - Division of Structural Biology & Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
Nobuo Tanaka - Electron microscope Lab., Ecotopia Science Institute and Dept. of Applied Physics, Nagoya University, Japan
Paul Verkade - Wolfson Bioimaging Facility, Schools of Biochemistry and Physiology & Pharmacology, Biomedical Sciences Building, University of Bristol, Bristol, UK
Dr Pécz, Béla Resolution and Discovery Institute of Technical Physics and Materials Science Centre for Energy Research, Hungarian Academy of Sciences H-1525 Budapest, PO Box 49, Hungary E-mail: email@example.com