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Origin of Ferroelectric Phase in Undoped HfO 2 Films Deposited by Sputtering
Author(s) -
Mittmann Terence,
Materano Monica,
Lomenzo Patrick D.,
Park Min Hyuk,
Stolichnov Igor,
Cavalieri Matteo,
Zhou Chuanzhen,
Chung ChingChang,
Jones Jacob L.,
Szyjka Thomas,
Müller Martina,
Kersch Alfred,
Mikolajick Thomas,
Schroeder Uwe
Publication year - 2019
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201900042
Subject(s) - materials science , ferroelectricity , orthorhombic crystal system , annealing (glass) , sputtering , monoclinic crystal system , thin film , analytical chemistry (journal) , diffraction , optoelectronics , dielectric , composite material , nanotechnology , crystallography , optics , crystal structure , physics , chromatography , chemistry
Thin film metal–insulator–metal capacitors with undoped HfO 2 as the insulator are fabricated by sputtering from ceramic targets and subsequently annealed. The influence of film thickness and annealing temperature is characterized by electrical and structural methods. After annealing, the films show distinct ferroelectric properties. Grazing incidence X‐ray diffraction measurements reveal a dominant ferroelectric orthorhombic phase for thicknesses in the 10–50 nm range and a negligible non‐ferroelectric monoclinic phase fraction. Sputtering HfO 2 with additional oxygen during the deposition decreases the remanent polarization. Overall, the impact of oxygen vacancies and interstitials in the HfO 2 film during deposition and annealing is correlated to the phase formation process.