TY - JOUR
T1 - Fabrication of ferroelectric Fe doped HfO2 epitaxial thin films by ion-beam sputtering method and their characterization
AU - Shiraishi, Takahisa
AU - Choi, Sujin
AU - Kiguchi, Takanori
AU - Shimizu, Takao
AU - Uchida, Hiroshi
AU - Funakubo, Hiroshi
AU - Konno, Toyohiko J.
N1 - Funding Information:
This research was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Nos. 17J03160, 16K18231, 16K14378, and 18H01701. Part of this work was also supported by Izumi Science and Technology Foundation. The support from K. Ohmura in Cooperative Research and Development Center for Advanced Materials is also acknowledged.
Publisher Copyright:
© 2018 The Japan Society of Applied Physics.
PY - 2018/11
Y1 - 2018/11
N2 - In this study, the effect of Fe doping on the crystal structure and electrical properties in 20-nm-thick HfO2 epitaxial thin films were systematically investigated. X-ray diffraction measurements revealed that undoped HfO2 films were composed of a paraelectric monoclinic phase. On the other hand, the formation of non-centrosymmetric orthorhombic phase was observed in Fe doped HfO2 films and was most promoted at an optimum doping concentration. In addition, high-temperature X-ray diffraction measurements showed that an orthorhombic phase to a highly symmetric phase transition occurs between 500 and 600 °C. Microstructural analysis using scanning transmission electron microscopy revealed multidomain structure consisting of orthorhombic and monoclinic phases. Ferroelectricity depended on Fe doping concentration, and the maximum remanent polarization value was 8.8 μC/cm2. These results indicate that Fe doped HfO2 thin films can be applied as nanoscale ferroelectrics.
AB - In this study, the effect of Fe doping on the crystal structure and electrical properties in 20-nm-thick HfO2 epitaxial thin films were systematically investigated. X-ray diffraction measurements revealed that undoped HfO2 films were composed of a paraelectric monoclinic phase. On the other hand, the formation of non-centrosymmetric orthorhombic phase was observed in Fe doped HfO2 films and was most promoted at an optimum doping concentration. In addition, high-temperature X-ray diffraction measurements showed that an orthorhombic phase to a highly symmetric phase transition occurs between 500 and 600 °C. Microstructural analysis using scanning transmission electron microscopy revealed multidomain structure consisting of orthorhombic and monoclinic phases. Ferroelectricity depended on Fe doping concentration, and the maximum remanent polarization value was 8.8 μC/cm2. These results indicate that Fe doped HfO2 thin films can be applied as nanoscale ferroelectrics.
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U2 - 10.7567/JJAP.57.11UF02
DO - 10.7567/JJAP.57.11UF02
M3 - Article
AN - SCOPUS:85057190881
SN - 0021-4922
VL - 57
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
IS - 11
M1 - 11UF02
ER -