title: Real-time identification of the evolution of conducting nano-filaments in TiO2 thin film ReRAM.
abstract: Unipolar resistance switching (RS) in TiO2 thin films originates from the repeated formation and rupture of the Magnéli phase conducting filaments through repeated nano-scale phase transitions. By applying the Johnson-Mehl-Avrami (JMA) type kinetic model to the careful analysis on the evolution of transient current in a pulse-switching, it was possible to elucidate the material specific evolution of the Magnéli phase filament. This methodology was applied to the two types of TiO2 films grown by plasma-enhanced atomic layer deposition (PEALD) and sputtering. These two samples have structurally and electrically distinctive properties: PEALD film exhibited high variability in switching parameters and required an electroforming while sputtered film showed higher uniformity without distinct electroforming process. The JMA-type kinetic analysis of the RS behaviors revealed that the rejuvenation of the filament is accomplished by repeated one-dimensional nucleation followed by a two-dimensional growth in PEALD samples, whereas one-dimensional nucleation-free mechanism dominates in sputtered films.
authors.affiliation: Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul, 151-744, Korea.
authors.forename: Seul Ji
authors.initials: SJ
authors.lastname: Song
authors.forename: Jun Yeong
authors.initials: JY
authors.lastname: Seok
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Yoon
authors.forename: Kyung Min
authors.initials: KM
authors.lastname: Kim
authors.forename: Gun Hwan
authors.initials: GH
authors.lastname: Kim
authors.forename: Min Hwan
authors.initials: MH
authors.lastname: Lee
authors.forename: Cheol Seong
authors.initials: CS
authors.lastname: Hwang