Hafnium oxide based ferroelectric materials for memory applications

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Abstract/Contents

Abstract
Innovations of memory technologies are essential for addressing the future needs of data processing and storage. The discovery of ferroelectricity in hafnia (HfO2)-based materials has led the re-emergence of ferroelectric memories in advanced semiconductor technologies, with the potential to reshape the technology landscape and to enable novel computing architectures. Ferroelectric HfO2 is promising for non-volatile memories (NVM) due to its ability to scale down to ultra-thin films and very small device dimensions. However, challenges are still present for implementation of ferroelectric HfO2 in commercial products developed for embedded memories, including limited programming cycle endurance and compatibility with the back-end-of-line (BEOL) processing temperature. This dissertation presents innovations at the material and device levels to realize high endurance and low thermal budget ferroelectric memories, followed by advanced material characterizations to probe the mechanisms behind. First, I will demonstrate an experimental investigation of ferroelectricity in CeO2 doped Hf0.5Zr0.5O2 (HZO) thin films.1 I will present an analysis encompassing measurements of switchable polarization, cycling endurance, stress-induced leakage current (SILC) and photoelectric effects to provide a comprehensive understanding of CeO2 doping effects on the conduction mechanism and reliability of CeO2-doped HZO polarization switching. Second, I will report an investigation of the crystal structure of ferroelectric HZO films as a function of atomic layer deposition (ALD) temperature. Our results suggests that optimization of HZO thin film synthesis defined by the ALD deposition temperature not only produces films with the highest ferroelectric polarization, but can achieve this at the low thermal budgets necessary for incorporation of ferroelectric HZO in BEOL devices.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2022; ©2022
Publication date 2022; 2022
Issuance monographic
Language English

Creators/Contributors

Author Yu, Zhouchangwan
Degree supervisor McIntyre, Paul Cameron
Thesis advisor McIntyre, Paul Cameron
Thesis advisor Nishi, Yoshio, 1940-
Thesis advisor Wong, Hon-Sum Philip, 1959-
Degree committee member Nishi, Yoshio, 1940-
Degree committee member Wong, Hon-Sum Philip, 1959-
Associated with Stanford University, Department of Electrical Engineering

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Zhouchangwan Yu.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis Ph.D. Stanford University 2022.
Location https://purl.stanford.edu/hn662hh8247

Access conditions

Copyright
© 2022 by Zhouchangwan Yu
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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