Zhao, ZefuZefuZhaoChen, Yu RuiYu RuiChenChen, Yun WenYun WenChenHsieh, Wan HsuanWan HsuanHsiehWang, Jer FuJer FuWangLee, Jia YangJia YangLeeXing, YifanYifanXingChen, Guan HuaGuan HuaChenCHEE-WEE LIU2023-10-172023-10-172023-01-01978486348806907431562https://scholars.lib.ntu.edu.tw/handle/123456789/636115Nearly epitaxially grown ferroelectric Hf0.5 Zr0.5 O2 (HZO) films on (001) n+-Si(3E19/cm 3) and n+ -Ge(3E20/cm 3) substrates exhibit record remanent polarization (2P r) of 84 and 73μC/cm2, respectively, which are higher than that on amorphous SiO2 (α-SiO2) and partially crystallized TiN underlayers. HZO films on n+ -Si and n+-Ge also show high coercive field (2Ec) of 8.8 and 5.8 MV/cm, respectively. Superlattice HZO films by plasma-enhanced atomic layer deposition (PEALD) show that c-axis is well-aligned with the growth direction in scanning transmission electron microscopy (STEM) images, consistent with observed high 2Pr of epitaxial HZO films on n+-Si(Ge). The density functional theory (DFT) indicates o-phase is greatly stabilized in the HZO films on n+- Si(Ge) substrates due to low interfacial energy at o-phase/Si(Ge) interfaces as compared to m-(t-)phase/Si(Ge). After 1E9 and 1E11 endurance cycles, the HZO on n+-Si and n+-Ge substrates have record finial 2P r of 51 and 47 μC/cm2, respectively. Our study demonstrates the way to achieve single crystalline ferroelectric HZO films by using small misfit substrates without interfacial layers. The thermal budget is as low as 450°C.conference paper10.23919/VLSITechnologyandCir57934.2023.101852332-s2.0-85167576722https://api.elsevier.com/content/abstract/scopus_id/85167576722