The research team* of Professor Yunseok Kim demonstrates a way to highly enhance the ferroelectricity of 

HfO₂-based ferroelectrics using ion bombardment.

* Co-corresponding authors: Prof. Young-Min Kim (SKKU), Dr. Jinseung Heo (Samsung Advanced Institute of Technology), Dr. Sergei Kalinin (Oak Ridge National Laboratory, USA)

Continuous advancement in nonvolatile and morphotropic beyond-Moore electronic devices necessitates the development of strategies that utilize the wealth of functionalities of complex materials at extremely reduced dimensions.

The discovery of ferroelectricity in hafnium oxide (HfO2)–based ferroelectrics that are compatible with the semiconductor process has opened interesting and promising avenues of research. However, the origins of ferroelectricity and pathways to controlling it in HfO2-based ferroelectrics are still mysterious.

We report that local ion bombardment can activate ferroelectricity in these materials. The possible competing mechanisms, including ion-induced molar volume changes, vacancy redistribution, vacancy generation, and activation of vacancy mobility, are discussed.

These findings including the variation of ferroelectricity through defect engineering based on ion bombardment suggest additional possibilities for ferroelectricity enhancement in HfO2-based ferroelectrics. Furthermore, this approach can be directly applied to a semiconductor process without structural modification and, thus, can increase its applicability in next-generation electronic devices, such as ultra-scaled ferroelectrics-based transistors and memories.

[Paper]
- “Highly enhanced ferroelectricity in HfO2-based ferroelectric thin film by light ion bombardment”, Science 376(6594), 731-738 (2022)
- URL: https://www.science.org/doi/10.1126/science.abk3195

□ Webpage: http://spm.skku.edu