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Title: Ferroelectricity emerging in strained (111)-textured ZrO{sub 2} thin films

(Anti-)ferroelectricity in complementary metal-oxide-semiconductor (CMOS)-compatible binary oxides have attracted considerable research interest recently. Here, we show that by using substrate-induced strain, the orthorhombic phase and the desired ferroelectricity could be achieved in ZrO{sub 2} thin films. Our theoretical analyses suggest that the strain imposed on the ZrO{sub 2} (111) film by the TiN/MgO (001) substrate would energetically favor the tetragonal (t) and orthorhombic (o) phases over the monoclinic (m) phase of ZrO{sub 2}, and the compressive strain along certain 〈11-2〉 directions may further stabilize the o-phase. Experimentally ZrO{sub 2} thin films are sputtered onto the MgO (001) substrates buffered by epitaxial TiN layers. ZrO{sub 2} thin films exhibit t- and o-phases, which are highly (111)-textured and strained, as evidenced by X-ray diffraction and transmission electron microscopy. Both polarization-electric field (P-E) loops and corresponding current responses to voltage stimulations measured with appropriate applied fields reveal the ferroelectric sub-loop behavior of the ZrO{sub 2} films at certain thicknesses, confirming that the ferroelectric o-phase has been developed in the strained (111)-textured ZrO{sub 2} films. However, further increasing the applied field leads to the disappearance of ferroelectric hysteresis, the possible reasons of which are discussed.
Authors:
; ; ; ; ; ;  [1] ; ;  [2] ;  [3]
  1. Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575 (Singapore)
  2. School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)
  3. Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore)
Publication Date:
OSTI Identifier:
22489251
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 1; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ELECTRIC POTENTIAL; EPITAXY; FERROELECTRIC MATERIALS; MAGNESIUM OXIDES; MONOCLINIC LATTICES; ORTHORHOMBIC LATTICES; SEMICONDUCTOR MATERIALS; STRAINS; SUBSTRATES; THICKNESS; THIN FILMS; TITANIUM NITRIDES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; ZIRCONIUM OXIDES