Ferroelectricity of Hf0.5Zr0.5O₂ Thin Films Free From the Influence of Electrodes by Using Al₂O₃ Capping Layers

• DOI: 10.1109/ted.2022.3146098
• Publication Date: 2022-02-21T21:50:55Z
• Authors: Jiaxian Wan; Xue Chen; Liwei Ji; Zexin Tu; Hao Wu; Chang Liu
• Keywords: 0103 physical sciences; 01 natural sciences

Ferroelectricity of Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Zr O xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> thin films prepared by plasma-enhanced atomic layer deposition (PEALD) with and without TiN electrodes was demonstrated. Excellent ferroelectricity confirmed both polarization versus voltage ( <inline-formula xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}$ </tex-math></inline-formula> ,– notation="LaTeX">${V}$ ) piezoresponse force microscopy (PFM) hysteresis loops. The notation="LaTeX">$2{P}_{r}$ value can reach as high notation="LaTeX">$53 ~\mu \text{C}$ /cm <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> under a sweep 8 V top bottom electrodes. By introducing Al xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> capping (AOCL), the sample notation="LaTeX">$47 \mu that is less sensitive to annealing temperatures electrode materials. At same time, leakage current also significantly reduced. typical loops always be observed for samples different materials or temperatures. These results are beneficial practical applications in nonvolatile memories synaptic devices.