Engineering Ferroelectric HZO with n+-Si/Ge Substrates Achieving High 2Pr =84 μC/cm2 and Endurance > 1E11
IEEE Access（2024）
摘要
Metal-Ferroelectric-Metal (MFM) devices possessing high remanent polarizations (2
Pr
) of 84 and 73 μC/cm
2
are demonstrated with nearly epitaxially grown Hf
0.5
Zr
0.5
O
2
(HZO) films on (001) n
+
-Si(3E19/cm
3
) and n
+
-Ge(3E20/cm
3
) substrates, respectively, which are higher than MFM devices with HZO films grown on amorphous SiO
2
and partially crystallized TiN underlayers/substrates. The HZO superlattice films by sequential ZrO
2
/HfO
2
plasma-enhanced atomic layer deposition (PEALD) process show high crystallinity in TEM images of all devices; however, the measured 2
Pr
values are quite different, ranging from 84 to 33μC/cm
2
. The high-resolution scanning transmission electron microscopy (HR-STEM) images of HZO films on n
+
-Si and n
+
-Ge show the polarization axis of o-phase is well-aligned with the growth direction which is consistent with observed high 2
Pr
values. Much lower interfacial energy at o-phase/Si(Ge) interfaces than m-(t-)phase/Si(Ge) by density functional theory (DFT) calculations indicates that o-phase is greatly stabilized in the HZO films on n
+
-Si(Ge) substrates. Strong 2
Pr
of 51 and 47 μC/cm
2
are measured after 1E9 and 1E11 endurance cycles for HZO films on n
+
-Si and n
+
-Ge substrates, respectively. This study shows epitaxial ferroelectric HZO films could be achieved by using small misfit substrates with the thermal budget as low as 450°C.
更多查看译文
关键词
Hf0.5Zr0.5O2,HZO,epitaxial growth,HR-STEM,PEALD,Interfacial energy,density functional theory
AI 理解论文
溯源树
样例
生成溯源树，研究论文发展脉络
Chat Paper
正在生成论文摘要