[16p-B508-1~17] 13.3 Insulator technology

[16p-B508-5] Stabilization of ferroelectric phase in HfO₂ thin films by applying mechanical strain during annealing process

〇Hiroshi Yasuda¹, Takashi Onaya², Koji Kita^1,2 (1.School of Eng., The Univ. of Tokyo, 2.Graduate School of Frontier Sci., The Univ. of Tokyo)

Keywords:HfO2-based ferroelectric films, mechanical strain

It has been considered that structural strain in tensile direction caused by substrates and electrodes stabilizes ferroelectric orthorhombic phase in HfO₂ thin films, but there are no reports which investigated the effect of structural strain experimentally and directly. In this study, we applied mechanical strain during annealing process and investigated the stabilization of orthorhombic phase directly and quantitatively. As a result, we found that tensile stress plays an important role to form and stabilize orthorhombic phase in HfO₂ films.