Activation energy distribution of dynamical structural defects in RuO${}_2$ films

Abstract

Ruthenium dioxide (RuO${}_2$) is an important metal widely used in nanoelectronic devices. It plays indispensable roles in the applications as catalyst and supercapacitors. A good understanding of the origin of the flicker or 1/$f$ noise in RuO${}_2$ will advance the design and efficiency of these applications. We demonstrate in a series of sputtered RuO${}_2$ polycrystalline films that the 1/$f$ noise originates from fluctuating oxygen vacancies which act as dynamical structural defects, i.e., moving scattering centers. Reducing the number of oxygen vacancies by adjusting thermal annealing conditions significantly reduces the noise magnitude $\gamma$, the Hooge parameter. We quantify the activation energy distribution function, $g(E)$, and calculate the oxygen vacancy density, $n_{TLS}$, from the measured $\gamma$ value. We show that $g(E)$ can be explicitly expressed in terms of $\gamma (T)$ and the electronic parameters of the metal, where $T$ denotes temperature. The inferred $n_{TLS}$ value is in line with the oxygen content determined from the x-ray photoelectron spectroscopy studies.

arXiv comment29 pages, 7 figures

References in corpus (7)

• Review of the Low-Frequency 1/f Noise in Graphene Devices
• 1/f noise: implications for solid-state quantum information
• Frequency fluctuations in silicon nanoresonators
• Frequency and phase noise of ultra-high Q silicon nitride nanomechanical resonators
• Ultralow 1/f Noise in a Heterostructure of Superconducting Epitaxial Cobalt-Disilicide Thin Film on Silicon
• Temporal universal conductance fluctuations in RuO${}_2$ nanowires due to mobile defects
• Probing nanocrystalline grain dynamics in nanodevices

Cited by in corpus (4)

• Oxygen vacancy-driven orbital multichannel Kondo effect in Dirac nodal line metals IrO2 and RuO2
• Quantum-interference origin and magnitude of 1/$f$ noise in Dirac nodal line IrO${}_2$ nanowires at low temperatures
• 1/ f noise and two-level systems in MBE-grown Al thin films
• Probing Thermally Activated Atomic and Nanocrystalline Defect Motion through Noise Processes in RuO${}_2$ Nanowires