Enhanced ferroelectric polarization with less wake-up effect and improved endurance of Hf0.5Zr0.5O2 thin films by implementing W electrode

Dao Wang, Yan Zhang, Jiali Wang, Chunlai Luo, Ming Li, Wentao Shuai, Ruiqiang Tao, Zhen Fan, Deyang Chen, Min Zeng, Jiyan Y. Dai, Xubing B. Lu, J. M. Liu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

1 Citation (Scopus)

Abstract

This paper reports the improvement of electrical, ferroelectric and endurance of Hf0.5Zr0.5O2 (HZO) thin-film capacitors by implementing W electrode. The W/HZO/W capacitor shows excellent pristine 2Pr values of 45.1 μC/cm2 at ±6 V, which are much higher than those of TiN/HZO/W (34.4 μC/cm2) and W/HZO/TiN (26.9 μC/cm2) capacitors. Notably, the maximum initial 2Pr value of W/HZO/W capacitor can reach as high as 57.9 μC/cm2 at ±7.5 V. These strong ferroelectric polarization effects are ascribed to the W electrode with a fairly low thermal expansion coefficient which provides a larger in-plane tensile strain compared with TiN electrode, allowing for enhancement of o-phase formation. Moreover, the W/HZO/W capacitor also exhibits higher endurance, smaller wake-up effect (10.1%) and superior fatigue properties up to 1.5 × 1010cycles compared to the TiN/HZO/W and W/HZO/TiN capacitors. Such improvements of W/HZO/W capacitor are mainly due to the decreased leakage current by more than an order of magnitude compared to the W/HZO/TiN capacitor. These results demonstrate that capping electrode material plays an important role in the enhancement of o-phase formation, reduces oxygen vacancies, mitigates wake-up effect and improves reliability.

Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalJournal of Materials Science and Technology
Volume104
DOIs
Publication statusPublished - 30 Mar 2022

Keywords

  • Endurance properties
  • Ferroelectric polarization
  • HfZrO films
  • Thermal expansion coefficient
  • W electrode

ASJC Scopus subject areas

  • Ceramics and Composites
  • Mechanics of Materials
  • Mechanical Engineering
  • Polymers and Plastics
  • Metals and Alloys
  • Materials Chemistry

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