Noise Fingerprints as a Quantitative Order Parameter for Polarization- and Defect-Mediated Switching in Hafnia...

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 O₃ dose time during HfZrO atomic layer deposition (ALD), the normalized power spectral density (S_I/I²) 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 O₃ 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.