Effects of deposition conditions on the ferroelectric properties of (Al1-xScx)N thin films
Effects of deposition conditions on the ferroelectric properties of (Al1-xScx)N thin films
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DOI：
10.1063/5.0015281
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发表时间：
2020-09-21
影响因子：
3.2
通讯作者：
Funakubo, Hiroshi
中科院分区：
文献类型：
--
作者：
Yasuoka, Shinnosuke;Shimizu, Takao;Funakubo, Hiroshi
研究了不同厚度的(Al1-xScx)N(x=0-0.34)薄膜的铁电性。采用射频双源反应磁控溅射方法，以Al和Sc为靶材，在纯N-2气体或N-2和Ar混合气体中，在400℃的温度下在(111)Pt/TiOx/SiO_2/(001)Si衬底上制备了(Al1-xScx)N薄膜。在N-2气体中沉积的薄膜比在N-2+Ar混合气体中沉积的薄膜具有更大的剩余极化。在氮气气氛下沉积的约140 nm厚的薄膜，x=0.10-0.34的薄膜具有铁电性。极化-电场曲线和正-上-负-下测量表明，x=0.22薄膜具有铁电性，厚度为48 nm。扫描非线性介电显微镜测量也证实了9 nm厚薄膜的铁电性。这些结果表明，与先前的研究相比，铁电极化可以切换到成分和厚度都更宽的薄膜。
The ferroelectricity of (Al1-xScx)N (x=0-0.34) thin films with various thicknesses was investigated. (Al1-xScx)N films were prepared at 400 degrees C on (111)Pt/TiOx/SiO2/(001)Si substrates by the radio frequency dual-source reactive magnetron sputtering method using Al and Sc targets under pure N-2 gas or a mixture of N-2 and Ar gases. The film deposited under N-2 gas showed larger remanent polarization than those under N-2 + Ar mixture. Ferroelectricity was observed for films with x=0.10-0.34 for about 140-nm-thick films deposited under N-2 gas. The x=0.22 films showed ferroelectricity down to 48nm in thickness from the polarization-electric field curves and the positive-up-negative-down measurement. The ferroelectricity of the 9nm-thick film also was ascertained from scanning nonlinear dielectric microscopy measurement. These results reveal that ferroelectric polarization can switch for films with much broader compositions and thicknesses than those in the previous study.