Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices

Abstract

About ten years after ferroelectricity was first reported in doped HfO2 polycrystalline films, there is tremendous interest in this material and ferroelectric oxides are once again in the spotlight of the memories industry. Great efforts are being made to understand and control ferroelectric properties. Epitaxial films, which have fewer defects and a more controlled microstructure than polycrystalline films, can be very useful for this purpose. Epitaxial films of ferroelectric HfO2 have been much less investigated, but after the first report in 2015 significant progress has been achieved. This review summarizes and discusses the main advances on epitaxial HfO2, considering growth, study of structural and ferroelectric properties, identification of the ferroelectric phase, and fabrication of devices. We hope this review will help researchers investigating epitaxial HfO2. It can also help extend the interest of the ferroelectric HfO2 community, now basically focused on polycrystalline samples, to epitaxial films.

Review

References in corpus (15)

• The Origin of Ferroelectricity in Hf${}_x$ Zr${}_{1-x}$ O${}_2$: A Computational Investigation and a Surface Energy Model
• Pathways Towards Ferroelectricity in Hafnia
• Kinetically-stabilized Ferroelectricity in Bulk Singlecrystalline HfO2:Y without Wake-up Effects
• Electroresistance effects in ferroelectric tunnel barriers
• Suppressed dependence of polarization on epitaxial strain in highly polar ferroelectrics
• High polarization, endurance and retention in sub-5 nm Hf${}_{0.5}$Zr${}_{0.5}$O${}_2$ films
• Growth Window of Ferroelectric Epitaxial Hf0.5Zr0.5O2 Thin Films
• Domain Matching Epitaxy of Ferroelectric Hf0.5Zr0.5O2(111) on La2/3Sr1/3MnO3(001)
• Enhanced ferroelectricity in epitaxial Hf0.5Zr0.5O2 thin films integrated with Si(001) using SrTiO3 templates
• Epitaxial Ferroelectric La-doped Hf0.5Zr0.5O2 Thin Films
• Blocking of conducting channels widens window for ferroelectric resistive switching in interface-engineered Hf0.5Zr0.5O2 tunnel devices
• Epitaxial Integration on Si(001) of Ferroelectric Hf0.5Zr0.5O2 Capacitors with High Retention and Endurance
• Unraveling ferroelectric polarization and ionic contributions to electroresistance in epitaxial Hf0.5Zr0.5O2 tunnel junctions
• Critical Effect of Bottom Electrode on Ferroelectricity of Epitaxial Hf0.5Zr0.5O2 Thin Films
• Fatigue and retention in the growth window of ferroelectric Hf0.5Zr0.5O2 thin films

Cited by in corpus (7)

• Polarization and resistive switching in epitaxial 2 nm Hf${}_{0.5}$Zr${}_{0.5}$O${}_2$ tunnel junctions
• Progress in Computational Understanding of Ferroelectric Mechanisms in HfO${}_2$
• Disentangling stress and strain effects in ferroelectric HfO2
• Epitaxial ferroelectric hafnia stabilized by symmetry constraints
• Origin of Interstitial Doping Induced Coercive Field Reduction in Ferroelectric Hafnia
• Theoretical lower limit of coercive field in ferroelectric hafnia
• Vanadium-doped HfO${}_2$, multiferroic uncompromised