첨단소재시스템연구소 초청 세미나-부산대 박민혁 교수님
*일시: 2019. 7. 8.(월) 오후 1:30-2:30 / 과학관 207호
Introduction to the ferroelectricity in HfO2 based thin films
Min Hyuk Park*
School of Materials Science and Engineering, Pusan National University,
Ferroelectric materials have been considered as an ideal material for nonvolatile memory applications due to their two spontaneous polarization states. However, materials issues which is related to the scaling down of the memory devices for high information storage density hindered the commercialization of ferroelectric memories such as ferroelectric random access memories and ferroelectric field-effect-transistors. Conventional ferroelectric materials based on perovskite or layered perovskite structure are not Si-compatible and it was almost impossible to deposit conventional ferroelectric materials on three dimensional nanostructures which is essential for state-of-the-art memory devices. In 2011, ferroelectricity in Si doped HfO2 thin films was reported by Boescke et al., and has attracted increasing interest in the field of ferroelectrics and memories.[1,2] Although ferroelectric phase cannot be found in the phase diagrams of bulk HfO2 or ZrO2, the ferroelectricity could be induced by various dopants and deposition techniques. Different from conventional ferroelectrics, fluorite structure ferroelectrics could show robust ferroelectricity even below 10 nm, and be homogeneously deposited on three dimensional nanostructures.[2-4] In this presentation, recent progresses in researches on ferroelectricity and/or antiferroelectricity in fluorite structure oxides will be comprehensively reviewed.
References
[1] T. S. Boescke et al. Appl. Phys. Lett. 99 (2011) 102903.
[2] M. H. Park et al. Adv. Mater. 27 (2015) 1811.
[3] T. Mikolajick et al. MRS Bull. 43 (2018) 840.
[4] M. H. Park et al. MRS Commun. 8 (2018) 795.