Effects of Capping Electrode on Ferroelectric Properties of Hf0.5Zr0.5O2 Thin Films
| Autor: | Wei Wang, Xumeng Zhang, Ming Liu, Yan Wang, Rongrong Cao, Xiaolong Zhao, Qi Liu, Hangbing Lv, Shengjie Zhao, Yang Yang |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Annealing (metallurgy) Analytical chemistry chemistry.chemical_element 02 engineering and technology Coercivity 021001 nanoscience & nanotechnology 01 natural sciences Ferroelectricity Positive direction Electronic Optical and Magnetic Materials chemistry Electric field 0103 physical sciences Electrode Electrical and Electronic Engineering Thin film 0210 nano-technology Tin |
| Zdroj: | IEEE Electron Device Letters. 39:1207-1210 |
| ISSN: | 1558-0563 0741-3106 |
| DOI: | 10.1109/led.2018.2846570 |
| Popis: | In this letter, effects of top electrodes (TEs) on ferroelectric properties of Hf0.5 Zr0.5 O2 (HZO) thin films are examined systematically. The remnant polarization (Pr) of HZO thin films increases by altering TEs with lower thermal expansions coefficient ( $\alpha $ ). The largest 2Pr value of 38.72 $\mu \text{C}$ /cm2 is observed for W TE with $\alpha = 4.5\times 10^{\mathsf {-6}}$ /K, while the 2Pr value is only $22.83~\mu \text{C}$ /cm2 for Au TE with $\alpha = 14.2\times 10^{\mathsf {-6}}$ /K. Meanwhile, coercive field (Ec) shifts along the electric field axis and the offset is found to be dependent on the difference of workfunctions (WFs) between TE and TiN bottom electrode (BE). Ec shifts toward negative/positive direction, when the WF of TE is larger/smaller (Pt, Pd, Au/W, Al, Ta) than TiN BE. This letter provides an effective way to modulate HfO2-based device performance for different requirements in actual application. |
| Databáze: | OpenAIRE |
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