Role of Oxygen Defects in Conductive-Filament Formation in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msub><mml:mi mathvariant="normal">Y</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>-Based Analog RRAM Devices as Revealed by Fluctuation Spectroscopy

Abstract

Analog resistive memory devices based on yttrium oxide exhibit universal noise behavior, due to the intrinsically high density of oxygen defects in the functional material. Utilizing fluctuation spectroscopy, noise of approximately $1/f$ type is found for resistance states both below and above the quantum conductance level. Moreover, the noise magnitude is reduced over repeated write/erase operations, a striking phenomenon that is explained as the consequence of the stabilization of the conducting filament via the consumption of nearby oxygen vacancies. This potential for ``endurance training'' makes the system promising for both nonvolatile memory and neuromorphic computing hardware.