Fast Switching and High Polarization in Ferroelectric Hf _0.5 Zr _0.5 O ₂ Films

HfO₂-based ferroelectric thin films exhibit promising potential for next-generation nonvolatile memories and neuromorphic devices. Achieving both high polarization and fast switching is required, but optimizing one of them can be at the cost of degrading the other. This study achieves simultaneous fast switching and high polarization in Hf_0.5Zr_0.5O₂ epitaxial films grown by pulsed laser deposition. The influence of redox conditions during film growth on the ferroelectric switching kinetics and domain wall motion is systematically explored. Switching spectroscopy and Rayleigh analysis reveal that optimized redox conditions, tuned by oxygen and argon pressures during Hf_0.5Zr_0.5O₂ deposition, enable both enhanced polarization and switching speeds. Switching time can be further shortened when the final polarization state is aligned with the internal electric fields. The study challenges the trade-off between switching speed and polarization, demonstrating that precise control of defects in the film can simultaneously optimize both.