Growth and ferroelectric properties of yttrium-doped hafnium oxide/indium-tin oxide polycrystalline heterostructures with sharp and uniform interfaces
Growth and ferroelectric properties of yttrium-doped hafnium oxide/indium-tin oxide polycrystalline heterostructures with sharp and uniform interfaces
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DOI：
10.1063/1.5046866
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发表时间：
2018-09
影响因子：
3.2
通讯作者：
H. Yamada;Y. Toyosaki;A. Sawa
中科院分区：
文献类型：
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作者：
H. Yamada;Y. Toyosaki;A. Sawa
我们报告了在氧化铟锡 (ITO) 层上大面积具有尖锐且均匀界面的多晶钇掺杂 5% HfO2 (YHO) 薄膜的生长及其铁电特性。在热氧化硅基底上，通过脉冲激光沉积以非晶形式沉积 YHO/ITO 双层，随后通过低温和高温两步沉积后退火 (PDA) 进行结晶。结晶的 YHO/ITO 异质结构具有超平坦的表面：原子力显微镜图像在 100 μm2 的面积上表现出 0.15 nm 的均方根粗糙度。其粗糙度远小于单组分ITO多晶薄膜。 X 射线衍射和透射电子显微镜 (TEM) 表明 YHO 在更高对称性相中形成，包括铁电正交 (o) YHO。 TEM 还证实了 YHO 层以伪相干方式从 YHO/ITO 界面结晶，并由此产生尖锐且均匀的 YHO/ITO 界面。
We report on the growth of polycrystalline yttrium-5%-doped HfO2 (YHO) films with sharp and uniform interfaces over a large area on indium-tin oxide (ITO) layers and their ferroelectric properties. On substrates of thermally oxidized silicon, YHO/ITO bilayers were deposited in amorphous form by means of pulsed-laser deposition and were subsequently crystalized by two-step post-deposition annealing (PDA) at low and high temperatures. The crystallized YHO/ITO heterostructures had ultraflat surfaces: atomic-force-microscopy images exhibited a root-mean-square roughness of 0.15 nm over an area of 100 μm2. The roughness was much smaller than that of single-component polycrystalline films of ITO. X-ray diffraction and transmission electron microscopy (TEM) suggested the formation of YHO in higher symmetry phases including ferroelectric orthorhombic (o) YHO. TEM also confirmed crystallization of YHO layers in a pseudo-coherent manner from the YHO/ITO interfaces and resultant sharp and uniform YHO/ITO interfaces....