Abstract
In the present work, we study the initial SET mechanism of resistive switching (RS) in Pt/HfO2/Ti devices under a static electrical stress and the RS mechanism under a bias sweeping mode with rates of 100 mV/s–300 mV/s. We characterize the thin HfO2 dielectric layer by x-ray photoelectron spectroscopy and x-ray diffraction. These findings show that the layer structure is stoichiometric and nanocrystalline with a crystal diameter of ∼ 14 Å. We measure the temporal dependence of the conductive filament growth at different temperatures and for various biases. Furthermore, these devices present stable bipolar resistive switching with a high-to-low resistive state (HRS/LRS) ratio of more than three orders of magnitude. Activation energy ERS ≈ 0.56 eV and drift current parameter V0 ≈ 0.07 V were determined from the temporal dependence of the initial ‘SET’ process, first HRS to LRS transition [for static electrical stress of VDS = (4.7–5.0 V)]. We analyze the results according to our model suggesting generation of double-charge oxygen vacancies at the anode and their diffusion across the dielectric layer. The double-charge vacancies transform to a single charge and then to neutral vacancies by capturing hot electrons, and form a conductive filament as soon as a critical neutral-vacancy cluster is formed across the dielectric layer.
Original language | English |
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Pages (from-to) | 1505-1511 |
Number of pages | 7 |
Journal | Journal of Electronic Materials |
Volume | 47 |
Issue number | 2 |
DOIs | |
State | Published - 1 Feb 2018 |
Keywords
- Resistive switching
- conductive filament
- hafnium oxide
- vacancies
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering