Enhancement of ferroelectricity and homogeneity of orthorhombic phase in Hf0.5Zr0.5O2thin films

Zhengmiao Zou; Guo Tian; Dao Wang; Yan Zhang; Jiali Wang; Yushan Li; Ruiqiang Tao; Zhen Fan; Deyang Chen; Min Zeng; Xingsen Gao; Ji-Yan Dai; Xubing Lu; J-M Liu

doi:10.1088/1361-6528/abfc70

Enhancement of ferroelectricity and homogeneity of orthorhombic phase in Hf_0.5Zr_0.5O₂thin films

Nanotechnology. 2021 May 26;32(33). doi: 10.1088/1361-6528/abfc70.

Authors

Zhengmiao Zou¹, Guo Tian¹, Dao Wang¹, Yan Zhang¹, Jiali Wang¹, Yushan Li¹, Ruiqiang Tao¹, Zhen Fan¹, Deyang Chen^{1

2}, Min Zeng¹, Xingsen Gao¹, Ji-Yan Dai², Xubing Lu¹, J-M Liu^{1

3}

Affiliations

¹ Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, People's Republic of China.
² Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China.
³ Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China.

PMID: 33910189
DOI: 10.1088/1361-6528/abfc70

Abstract

By adoption of a high permittivity ZrO₂capping layer (ZOCL), enhanced ferroelectric properties were achieved in the Hf_0.5Zr_0.5O₂(HZO) thin films. For HZO thin film with 10 Å ZOCL, the 2P_rvalue can reach as high as ∼43.1μC cm^-2under a sweep electric field of 3 MV cm^-1. In addition, a reduced coercive field of 1.5 MV cm^-1was observed, which is comparable to that of HZO with metallic CL. Furthermore, the homogeneity of ferroelectric orthorhombic phase in HZO films was observed to be clearly increased, as evidenced by nanoscale piezoelectric force microscopy measurements. These results demonstrate that ZOCL is very favorable for high performance ferroelectric HZO films and their future device applications.

Keywords: Hf0.5Zr0.5O2; ZrO2; capping layer; ferroelectricity.