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Understanding the stress effect of TiN top electrode on ferroelectricity in Hf0.5Zr0.5O2 thin films.

Authors :
Han, Runhao
Hong, Peizhen
Zhang, Bao
Bai, Mingkai
Hou, Jingwen
Yang, Jinchuan
Xiong, Wenjuan
Yang, Shuai
Gao, Jianfeng
Lu, Yihong
Liu, Fei
Luo, Feng
Huo, Zongliang
Source :
Journal of Applied Physics. 11/21/2023, Vol. 134 Issue 19, p1-9. 9p.
Publication Year :
2023

Abstract

We conducted a comprehensive investigation on the influence of TiN thickness and stress on the ferroelectric properties of Hf 0.5 Zr 0.5 O 2 thin films. TiN top electrode layers with varying thicknesses of 2, 5, 10, 30, 50, 75, and 100 nm were deposited and analyzed. It was observed that the in-plane tensile stress in TiN films increased with the thickness of the TiN top electrode. This is expected to elevate the tensile stress in the Hf 0.5 Zr 0.5 O 2 film, consequently leading to an enhancement in ferroelectric polarization. However, the effect of stress on the ferroelectric behavior of Hf 0.5 Zr 0.5 O 2 films exhibited distinct stages: improvement, saturation, and degradation. Our study presents novel findings revealing a saturation and degradation phenomenon of in-plane tensile stress on the ferroelectric properties of polycrystalline Hf 0.5 Zr 0.5 O 2 films, thereby partially resolving the discrepancies between experimental observations and theoretical predictions. The observed phase transformation induced by tensile stress in Hf 0.5 Zr 0.5 O 2 films played a crucial role in these effects. Furthermore, we found that the impact of the TiN top electrode thickness on other factors influencing ferroelectricity, such as grain size and oxygen vacancies, was negligible. These comprehensive results offer valuable insights into the influence of stress and TiN top electrode thickness on the ferroelectric behavior of Hf 0.5 Zr 0.5 O 2 films. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00218979
Volume :
134
Issue :
19
Database :
Academic Search Index
Journal :
Journal of Applied Physics
Publication Type :
Academic Journal
Accession number :
173743938
Full Text :
https://doi.org/10.1063/5.0176345