Wake-up-mitigated giant ferroelectricity in Hf0.5Zr0.5O2 thin films through oxygen-providing, surface-oxidized W electrode

Abstract

The ferroelectricity of Hf0.5Zr0.5O2 thin films makes them good candidate materials for current and future electronic devices. To maximize the remanent polarization of Hf0.5Zr0.5O2, a new strategy is proposed to provide oxygen from a surface-oxidized W electrode. The ferroelectricity of Hf0.5Zr0.5O2 thin films with top and bottom TiN or W electrodes was compared to understand the effects of oxygen supply from the electrodes. Employing W top and bottom electrodes resulted in a double remanent polarization value of up to ∼60.25 μC/cm2; additionally, the wake-up effect was weaker than that observed when the TiN electrodes were used. The oxygen supply from the W electrode increased the grain radius by 161.34%, resulting in a 204.01% increase in remanent polarization. This suggests that the electrode material is a critical determinant of the ferroelectric properties of Hf0.5Zr0.5O2.