[20p-C309-1~10] Applications of new ferroelecric materials for the future electric devices

[20p-C309-5] Microstructural Change in Hf_0.5Zr_0.5O₂Ferroelectric Thin Films during Phase Transformation

〇Shinji Migita¹, Hiroyuki Ota¹, Yukinori Morita¹ (1.AIST)

Keywords:ferroelectric, HfO2, phase transformation

Phase transformation of Hf-Zr-O films with the annealing condition is investigated. It is shown that depending on the thermal budge, the crystal structures of Hf-Zr-O films change in the order of the tetragonal, the orthorhombic, and finally the monoclinic phase. Because the unit cell volume of the monoclinic phase is large, its transformaion accompanies the volume expansion. As a result, crystal grains are segmented into periodical small regions.