In this Letter, a high-pressure annealing (HPA) process is proposed as a way to reduce the thermal budget of Hf0.5Zr0.5O2 (HZO) thin films with ferroelectric behaviors. The low-thermal-budget process is essential for integrating ferroelectric devices in the back-end-of-line to provide more functionalities and effective memory area. For the HZO film annealed at 300 °C using the HPA process, an orthorhombic phase responsible for ferroelectric behavior was formed with a decrease in film thickness, resulting in a remanent polarization (Pr) of ∼13 μC/cm2 (i.e., 2Pr of ∼26 μC/cm2). Meanwhile, when only the annealing time was increased at 300 °C without applying pressure, the HZO film did not crystallize and exhibited linear dielectric properties. Consequently, the HZO films (<10 nm) can be crystallized by applying pressure (15 atm) even at low temperatures of 300 °C, thereby obtaining ferroelectric properties.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2019R1F1A1059972) and GRC-LMD program (No. 3001.001) of SRC. This work was also partially supported by the Korea Institute for Advancement of Technology (KIAT) grant (No. P0017011, HRD Program for Industrial Innovation) and Technology Innovation Program (No. 20010806) funded by the Korea government (MOTIE). The ozone generator used in this work was provided by Toshiba-Mitsubishi-Electric Industrial Systems Corporation (TMEIC).
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All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)