Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 8, Issue 24, Pages 15466-15475Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.6b03586
Keywords
hafnium oxide; ferroelectrics; wake-up; endurance; nonvolatile memory
Funding
- Global Research Laboratory Program of the Ministry of Science, ICT, and Future Planning of the Republic of Korea [2012K1A1A2040157]
- National Research Foundation of Korea (NRF) - South Korean government (MSIP) [2014R1A2A1A10052979]
Ask authors/readers for more resources
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
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available