Texture modulation of ferroelectric Hf0.5Zr0.5O2 thin films by engineering the polymorphism and texture of tungsten electrodes

Abstract

This study proposes a novel approach to achieving highly reliable, low-voltage polarization switching of ferroelectric Hf_0.5Zr_0.5O₂ (HZO) thin films using polymorph- and orientation-controlled W electrodes ((111)-textured α-W and (200)-textured β-W) by adjusting the sputtering conditions. We demonstrated the formation of (111) and (002)/(020)-textured HZO films on the (111)-textured α-W and (200)-textured β-W electrodes, respectively. Under a low-voltage pulse of 1.2 V (1.5 MV/cm), α-W/HZO/α-W and β-W/HZO/β-W capacitors exhibited double-remanent polarization (2P_r) values of 29.23 μC/cm² and 25.16 μC/cm², which were higher than that of the TiN/HZO/TiN capacitor by 33% and 14%, respectively, and a high endurance of 10⁹ cycles without hard-breakdown. The differences in the ferroelectric properties and switching kinetics were understood based on the polymorphism and texture of the HZO films influenced by electrode materials.