Noise Fingerprints as a Quantitative Order Parameter for Polarization‐ and Defect‐Mediated Switching in Hafnia Ferroelectrics

ABSTRACT Noise, often regarded as an unwanted background in electronic devices, can instead serve as a sensitive probe of switching dynamics. In hafnia ferroelectrics, the coexistence of polarization‐mediated (P‐RS) and defect‐mediated (D‐RS) resistance switching has been widely debated, yet prior evidence has remained qualitative. Here, we demonstrate that low‐frequency noise (LFN) can be transformed into a quantitative order parameter that disentangles the two mechanisms across program bias ( V _PGM ) and processing conditions. By varying the O ₃ dose time during HfZrO atomic layer deposition (ALD), the normalized power spectral density ( S _I / I ² ) consistently exhibits a rise–peak–fall profile. We introduce a deconvolution framework, grounded in monotonic baselines and alternating projections, to extract physically consistent polarization‐ and defect‐mediated current components. The resulting process‐bias maps show that reduced O ₃ dose shifts the P‐RS/D‐RS crossover to lower V _PGM and sharpens the transition, directly linking oxygen stoichiometry to the competition between switching pathways. This quantitative approach resolves the long‐standing controversy over P‐RS and D‐RS coexistence and provides practical guidance for the design of hafnia‐based ferroelectric devices.