Electron holography on HfO2/HfO2−x bilayer structures with multilevel resistive switching properties. (2nd May 2017)

• Record Type: Journal Article
• Authors: Niu, G; Schubert, M A; Sharath, S U; Zaumseil, P; Vogel, S; Wenger, C; Hildebrandt, E; Bhupathi, S; Perez, E; Alff, L; Lehmann, M; Schroeder, T; Niermann, T
• Is Part Of: Nanotechnology. Volume 28:Number 21(2017)
• Publication Date: 2017-05-02
• Subjects: RRAM -- electron holography -- HfO2 -- resistive switching -- multi-level; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/aa6cd9
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Unveiling the physical nature of the oxygen-deficient conductive filaments (CFs) that are responsible for the resistive switching of the HfO2 -based resistive random access memory (RRAM) devices represents a challenging task due to the oxygen vacancy related defect nature and nanometer size of the CFs. As a first important step to this goal, we demonstrate in this work direct visualization and a study of physico–chemical properties of oxygen-deficient amorphous HfO2− x by carrying out transmission electron microscopy electron holography as well as energy dispersive x-ray spectroscopy on HfO2 /HfO2− x bilayer heterostructures, which are realized by reactive molecular beam epitaxy. Furthermore, compared to single layer devices, Pt/HfO2 /HfO2− x /TiN bilayer devices show enhanced resistive switching characteristics with multilevel behavior, indicating their potential as electronic synapses in future neuromorphic computing applications.