Elucidation of Design Principles for Low-Voltage Switching in Next-Generation Memory Materials / Research Team Led by Professor Cha Pil-Ryung (Department of New Materials Engineering)
Design of Dielectric and Semidielectric Layers Reduces Electric Field Loss by Up to 39%; Published in *Advanced Functional Materials*
- 26.09.07 / 홍유민
A research team led by Professor Cha Pil-Ryung from the Department of New Materials Engineering at Kookmin University has identified a design principle that allows for a reduction in device operating voltage in hafnium-zirconium oxide (HZO) thin films—a material gaining attention as a next-generation semiconductor memory material—based solely on the spatial arrangement of phases, rather than the material composition. These findings were published in *Advanced Functional Materials* (IF 19.9), a prestigious international journal in the field of materials science.
HZO thin films have garnered attention as materials for next-generation non-volatile memory and high-density capacitors due to their high compatibility with existing semiconductor processes. However, in actual thin films, ferroelectric (FE), antiferroelectric (AFE), and dielectric (DE) phases coexist in a complex manner, making it difficult to predict electrical properties based solely on phase fractions. Furthermore, the high coercive field required to reverse polarization has been a major obstacle, driving up both the operating voltage and power consumption.
The research team developed a three-dimensional phase-field model that describes the three phases as a single free-energy system while simultaneously accounting for the actual polycrystalline structure and interlayer electrostatic interactions, and validated the model using experimentally measured polarization curves.
The analysis revealed that switching in the thin film was governed not by long-range connections but by localized electrical interactions between adjacent FE and AFE grains, with a range of influence of 22–37 nm—similar to the average grain size. Furthermore, by intentionally arranging the two phases along the thickness direction of the thin film, the electric field could be reduced by up to 39% compared to a single-layer structure; in particular, the FE/AFE/FE sandwich structure emerged as the most efficient design, reducing the electric field by 23% while suppressing residual polarization loss to around 10%. This demonstrates that controllable phase arrangement can be utilized as a new design parameter for devices, rather than relying on difficult-to-control factors such as doping or defects.
Professor Cha Pil-Ryung stated, “This study quantitatively demonstrates that the electric field within a thin film can be actively controlled by adjusting the arrangement of ferroelectrics and antiferroelectrics,” adding, “We hope it will serve as a computation-based platform for designing low-voltage, high-efficiency memory devices.”
This research was led by Dr. P. Pankaj of Kookmin University as the first author, with Dr. Sandeep Sugathan of Kookmin University, Professor JiYoung Kim of the University of Texas at Dallas, and Professor Kim sijoon of Kangwon National University participating as co-researchers. The study was conducted with support from the Ministry of Science and ICT and the National Research Foundation of Korea.
[Research Support] Ministry of Science and ICT · National Research Foundation of Korea (RS-2024-00444182, RS-2024-00450836)
**[Paper Information]** P. Pankaj, S. Sugathan, J. Kim, S. J. Kim, P.-R. Cha, “Unified Phase-Field Framework for Antiferroelectric, Ferroelectric, and Dielectric Phases: Application to HZO Thin Films,” *Advanced Functional Materials*, 2026, e77910. (Open Access)
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This content is translated from Korean to English using the AI translation service DeepL and may contain translation errors such as jargon/pronouns. If you find any, please send your feedback to kookminpr@kookmin.ac.kr so we can correct them.
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Elucidation of Design Principles for Low-Voltage Switching in Next-Generation Memory Materials / Research Team Led by Professor Cha Pil-Ryung (Department of New Materials Engineering) Design of Dielectric and Semidielectric Layers Reduces Electric Field Loss by Up to 39%; Published in *Advanced Functional Materials* |
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A research team led by Professor Cha Pil-Ryung from the Department of New Materials Engineering at Kookmin University has identified a design principle that allows for a reduction in device operating voltage in hafnium-zirconium oxide (HZO) thin films—a material gaining attention as a next-generation semiconductor memory material—based solely on the spatial arrangement of phases, rather than the material composition. These findings were published in *Advanced Functional Materials* (IF 19.9), a prestigious international journal in the field of materials science. HZO thin films have garnered attention as materials for next-generation non-volatile memory and high-density capacitors due to their high compatibility with existing semiconductor processes. However, in actual thin films, ferroelectric (FE), antiferroelectric (AFE), and dielectric (DE) phases coexist in a complex manner, making it difficult to predict electrical properties based solely on phase fractions. Furthermore, the high coercive field required to reverse polarization has been a major obstacle, driving up both the operating voltage and power consumption. The research team developed a three-dimensional phase-field model that describes the three phases as a single free-energy system while simultaneously accounting for the actual polycrystalline structure and interlayer electrostatic interactions, and validated the model using experimentally measured polarization curves. The analysis revealed that switching in the thin film was governed not by long-range connections but by localized electrical interactions between adjacent FE and AFE grains, with a range of influence of 22–37 nm—similar to the average grain size. Furthermore, by intentionally arranging the two phases along the thickness direction of the thin film, the electric field could be reduced by up to 39% compared to a single-layer structure; in particular, the FE/AFE/FE sandwich structure emerged as the most efficient design, reducing the electric field by 23% while suppressing residual polarization loss to around 10%. This demonstrates that controllable phase arrangement can be utilized as a new design parameter for devices, rather than relying on difficult-to-control factors such as doping or defects. Professor Cha Pil-Ryung stated, “This study quantitatively demonstrates that the electric field within a thin film can be actively controlled by adjusting the arrangement of ferroelectrics and antiferroelectrics,” adding, “We hope it will serve as a computation-based platform for designing low-voltage, high-efficiency memory devices.” This research was led by Dr. P. Pankaj of Kookmin University as the first author, with Dr. Sandeep Sugathan of Kookmin University, Professor JiYoung Kim of the University of Texas at Dallas, and Professor Kim sijoon of Kangwon National University participating as co-researchers. The study was conducted with support from the Ministry of Science and ICT and the National Research Foundation of Korea. [Research Support] Ministry of Science and ICT · National Research Foundation of Korea (RS-2024-00444182, RS-2024-00450836) **[Paper Information]** P. Pankaj, S. Sugathan, J. Kim, S. J. Kim, P.-R. Cha, “Unified Phase-Field Framework for Antiferroelectric, Ferroelectric, and Dielectric Phases: Application to HZO Thin Films,” *Advanced Functional Materials*, 2026, e77910. (Open Access)
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