Guidelines for the stabilization of a polar rhombohedral phase in epitaxial Hf0.5Zr0.5O2 thin films

Abstract

The unconventional Si-compatible ferroelectricity in hafnia-based systems, which becomes robust only at nanoscopic sizes, has attracted a lot of interest. While a metastable polar orthorhombic (o-) phase (Pca21) is widely regarded as the responsible phase for ferroelectricity, a higher energy polar rhombohedral (r-) phase is recently reported on epitaxial HfZrO4 (HZO) films grown on (001) SrTiO3 (R3m or R3), (0001) GaN (R3), and Si (111). Armed with results on these systems, here we report a systematic study leading towards identifying comprehensive global trends for stabilizing r-phase polymorphs in epitaxially grown HZO thin films (6 nm) on various substrates (perovskites, hexagonal and Si).

arXiv commentFinal version as it appears in the 50th Anniversary issue of Ferroelectrics

References in corpus (12)

• The Origin of Ferroelectricity in Hf${}_x$ Zr${}_{1-x}$ O${}_2$: A Computational Investigation and a Surface Energy Model
• A rhombohedral ferroelectric phase in epitaxially-strained Hf0.5Zr0.5O2 thin films
• Engineering Ferroelectric Hf0.5Zr0.5O2 Thin Films by Epitaxial Stress
• Growth Window of Ferroelectric Epitaxial Hf0.5Zr0.5O2 Thin Films
• Effects of Growth Orientations and Epitaxial Strains on Phase Stability of HfO${}_2$ 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
• Coupling and competition between ferroelectricity, magnetism, strain and oxygen vacancies in AMnO3 perovskites
• Direct epitaxial growth of polar (1-x)HfO2-(x)ZrO2 ultra-thin films on Silicon
• Epitaxial Integration on Si(001) of Ferroelectric Hf0.5Zr0.5O2 Capacitors with High Retention and Endurance
• Magnetic tunnel junctions based on ferroelectric Hf0.5Zr0.5O2 tunnel barriers
• Stabilization of phase-pure rhombohedral HfZrO4 in Pulsed Laser Deposited thin films

Cited by in corpus (9)

• Intrinsic ferroelectricity in Y-doped HfO2 thin films
• Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices
• Epitaxial Ferroelectric La-doped Hf0.5Zr0.5O2 Thin Films
• Ferroelectricity in epitaxially strained rhombohedral ZrO2 thin films
• Flexoelectricity-stabilized ferroelectric phase with enhanced reliability in ultrathin La:HfO2 films
• Electrochemical control of ferroelectricity in hafnia-based ferroelectric devices using reversible oxygen migration
• Engineering ferroelectricity in monoclinic hafnia
• Operando observation of reversible oxygen migration and phase transitions in ferroelectric devices
• Guidelines for the optimization of hafnia-based ferroelectrics through superlattice engineering