title: Investigation of switching mechanism in HfOx-ReRAM under low power and conventional operation modes.
abstract: Low-power resistive random access memory (LP-ReRAM) devices have attracted increasing attention owing to their advantages of low operation power. In this study, a vertical-type LP-ReRAM consisting of TiN/Ti/HfO2/TiN structure was fabricated. The switching mechanism for LP-ReRAM was elucidated as the conductive filament mechanism for conventional mode, and an interface-type switching mechanism for low power mode was proposed. The analysis of low frequency noise shows that power spectral density (PSD) is approximately proportional to 1/f for conventional operation mode. Nevertheless, for low power mode, the PSD of low resistance state (LRS) is proportional to 1/f, while that of high resistance state (HRS) is clear proportional to 1/f2. The envelope of multiple Lorentzian spectra of 1/f2characteristics due to different traps reveals the characteristics of 1/f. For HRS of low power mode, a limited number of traps results in a characteristic of 1/f2. During the set process, the number of oxygen vacancies increases for LRS. Therefore, the PSD value is proportional to 1/f. Owing to the increase in the number of traps when the operation mode changes to conventional mode, the PSD value is proportional to 1/f. To the best of our knowledge, this is the first study that reveals the different noise characteristics in the low power operation mode from that in the conventional operation mode.
authors.affiliation: Nanoelectronics Research Institute (NeRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8560, Japan.
authors.forename: Wei
authors.initials: W
authors.lastname: Feng
authors.affiliation: Nanoelectronics Research Institute (NeRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8560, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Shima
authors.affiliation: Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, 305-8573, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohmori
authors.affiliation: Nanoelectronics Research Institute (NeRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8560, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Akinaga