Fatigue-Resistant Ferroelectric Hafnium Oxides by Modulating Grain Boundaries

Area of Science:

• Materials Science
• Solid State Physics
• Device Engineering

Background:

• High-endurance ferroelectric materials are crucial for in-memory computing, demanding reliable non-volatile memories for data storage and computation.
• Polarization fatigue in ferroelectric thin films limits device endurance, necessitating a deeper understanding of fatigue mechanisms.

Purpose of the Study:

• To investigate the role of grain boundaries (GBs) in polarization fatigue of ferroelectric hafnium oxide (HfO2) thin films.
• To develop fatigue-resistant Sm:HfO2 thin films with enhanced endurance for memory applications.

Main Methods:

• Fabrication of orientation-controllable orthorhombic Sm:HfO2 thin films.
• Analysis of grain boundary structures and their influence on ferroelectric domain switching.
• Characterization of polarization fatigue behavior and endurance performance.

Main Results:

• Modulating grain boundaries in Sm:HfO2 films significantly improved fatigue resistance.
• Eliminating GBs associated with phase transforms led to uniform 180° switching and a 200-fold increase in fatigue-free endurance (2.0 × 10^9 cycles).
• Achieved a large field-cycling non-volatile polarization of ~60 µC/cm² with state-of-the-art endurance.

Conclusions:

• Grain boundaries play a critical role in ferroelectric domain configurations and switching pathways, influencing polarization fatigue.
• Eliminating detrimental GBs offers a promising strategy for designing high-reliability hafnium oxide-based memories.
• The findings provide new insights into fatigue mechanisms and guide future material design for advanced memory devices.