title: Ultrathin Hf0.5Zr0.5O2 Ferroelectric Films on Si.
abstract: Because of their immense scalability and manufacturability potential, the HfO2-based ferroelectric films attract significant attention as strong candidates for application in ferroelectric memories and related electronic devices. Here, we report the ferroelectric behavior of ultrathin Hf0.5Zr0.5O2 films, with the thickness of just 2.5 nm, which makes them suitable for use in ferroelectric tunnel junctions, thereby further expanding the area of their practical application. Transmission electron microscopy and electron diffraction analysis of the films grown on highly doped Si substrates confirms formation of the fully crystalline non-centrosymmetric orthorhombic phase responsible for ferroelectricity in Hf0.5Zr0.5O2. Piezoresponse force microscopy and pulsed switching testing performed on the deposited top TiN electrodes provide further evidence of the ferroelectric behavior of the Hf0.5Zr0.5O2 films. The electronic band lineup at the top TiN/Hf0.5Zr0.5O2 interface and band bending at the adjacent n(+)-Si bottom layer attributed to the polarization charges in Hf0.5Zr0.5O2 have been determined using in situ X-ray photoelectron spectroscopy analysis. The obtained results represent a significant step toward the experimental implementation of Si-based ferroelectric tunnel junctions.
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
authors.forename: Anna
authors.initials: A
authors.lastname: Chernikova
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
authors.forename: Maksim
authors.initials: M
authors.lastname: Kozodaev
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
authors.forename: Andrei
authors.initials: A
authors.lastname: Markeev
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
authors.forename: Dmitrii
authors.initials: D
authors.lastname: Negrov
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
authors.forename: Maksim
authors.initials: M
authors.lastname: Spiridonov
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
authors.forename: Sergei
authors.initials: S
authors.lastname: Zarubin
authors.affiliation: Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States.
authors.forename: Ohheum
authors.initials: O
authors.lastname: Bak
authors.affiliation: Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States.
authors.forename: Pratyush
authors.initials: P
authors.lastname: Buragohain
authors.affiliation: Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States.
authors.forename: Haidong
authors.initials: H
authors.lastname: Lu
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.|École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland.|A.V. Shubnikov Institute of Crystallography, Leninsky pr. 59, Moscow 119333, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Suvorova
authors.affiliation: Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States.
authors.forename: Alexei
authors.initials: A
authors.lastname: Gruverman
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.|NRNU "Moscow Engineering Physics Institute", Moscow 115409, Russia.
authors.forename: Andrei
authors.initials: A
authors.lastname: Zenkevich
keywords: CMOS integration; ferroelectric switching; ferroelectric tunnel junctions; hafnium oxides; ultrathin films