title: Effect of Zr Content on the Wake-Up Effect in Hf1-xZrxO2 Films.
abstract: In this study, the changes in the structural and electrical properties of ferroelectric Hf1-xZrxO2 films with various Zr contents (0.26-0.70) were systematically examined during electric field cycling, resulting in a "wake-up" effect. To quantify the degree of wake-up effect, a "variable" polarization as the difference between remanent and saturation polarization was suggested as a new parameter, which could be calculated by excluding the linear dielectric contribution from the total electric displacement. Here, the variable polarization value could be minimized for an optimized Zr content of 0.43, which was slightly lower than the value for the largest remanent polarization. The polymorphism in Hf1-xZrxO2 thin films is known to be complicated due to the relatively small energy differences between various phases, such as the monoclinic, tetragonal, and orthorhombic phases. The variations in the polarization-electric field characteristics and dielectric constant values could be qualitatively and quantitatively understood based on the competition of various polymorphs that are dependent on the Zr content. Furthermore, a schematic model for the spatial distribution of mixed phases was suggested for Hf1-xZrxO2 films with various Zr contents based on the experimental observations.
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.|NaMLab gGmbH, Noethnitzer Strasse 64, 01187 Dresden, Germany.
authors.forename: Min Hyuk
authors.initials: MH
authors.lastname: Park
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.
authors.forename: Han Joon
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.
authors.forename: Yu Jin
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.
authors.forename: Taehwan
authors.initials: T
authors.lastname: Moon
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.
authors.forename: Keum Do
authors.initials: KD
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.
authors.forename: Seung Dam
authors.initials: SD
authors.lastname: Hyun
authors.affiliation: NaMLab gGmbH, Noethnitzer Strasse 64, 01187 Dresden, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Fengler
authors.affiliation: NaMLab gGmbH, Noethnitzer Strasse 64, 01187 Dresden, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Schroeder
authors.affiliation: Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University , Seoul 151-744, Republic of Korea.
authors.forename: Cheol Seong
authors.initials: CS
authors.lastname: Hwang
keywords: endurance; ferroelectrics; hafnium oxide; nonvolatile memory; wake-up