The effect of HfO2 on the magnetic anisotropy, electrical structure and microstructure of CoFeB/MgO films

doi:10.1016/j.jallcom.2017.07.142

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	The effect of HfO2 on the magnetic anisotropy, electrical structure and microstructure of CoFeB/MgO films
	Zhang, P; Shi, H; Li, MH; Chen, X; Fang, S; Han, G; Zhao, CJ; Wang, BY; Cao, XZ; Wang, DW
刊名	JOURNAL OF ALLOYS AND COMPOUNDS
	2017
卷号	725 页码:425-432
关键词	HfO2 CoFeB/MgO Magnetic anisotropy Film defects Oxygen migration
ISSN号	0925-8388
DOI	10.1016/j.jallcom.2017.07.142
文献子类	Article
英文摘要	Metal oxides are used in magnetic tunnel junctions to improve the magnetic properties and thermostability of materials in high-performance applications. In this study, an ultrathin Hf film is deposited on a Ta buffer layer. Moreover, subsequent annealing at 350 degrees C leads to the oxidation of Hf into HfO2, as confirmed by X-ray photoelectron spectrometry (XPS). The effect of HfO2 on magnetic anisotropy is evaluated in Ta/Hf/CoFeB/MgO/Ta multilayer films. Easy-axis magnetisation transition from in-plane to out-of-plane direction is observed at an annealing temperature of 200 degrees C. Moreover, the sample annealed at a temperature of 350 degrees C exhibits clear perpendicular magnetic anisotropy, which satisfies industry requirements in terms of annealing temperature for magnetic random access memory applications. XPS, positron annihilation spectroscopy (PAS), X-ray reflectivity (XRR) and atomic force microscopy (AFM) are used to study film composition, defects, interface width and surface roughness in Ta/Hf/CoFeB/MgO/Ta multilayers. XPS results demonstrate partial suppression of Ta atom diffusion and enhanced formation of Fe (Co) oxides in CoFeB/MgO. The results of PAS analysis suggest that the density of film defects decreases after annealing at 350 degrees C. XRR and AFM results reveal that annealing at 350 degrees C produces a smoother CoFeB/MgO interface. Together, these factors lead to improved magnetic properties and thermostability in a Ta/Hf/CoFeB/MgO/Ta film. (C) 2017 Elsevier B.V. All rights reserved.
电子版国际标准刊号	1873-4669
WOS关键词	PERPENDICULAR-ANISOTROPY ; OXIDE CATALYSTS ; INTERFACE
WOS研究方向	Chemistry ; Materials Science ; Metallurgy & Metallurgical Engineering
语种	英语
WOS记录号	WOS:000412332900050
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/285287]
专题	高能物理研究所_核技术应用研究中心高能物理研究所_实验物理中心高能物理研究所_多学科研究中心
作者单位	中国科学院高能物理研究所
推荐引用方式 GB/T 7714	Zhang, P,Shi, H,Li, MH,et al. The effect of HfO2 on the magnetic anisotropy, electrical structure and microstructure of CoFeB/MgO films[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2017,725:425-432.
APA	Zhang, P.,Shi, H.,Li, MH.,Chen, X.,Fang, S.,...&曹兴忠.(2017).The effect of HfO2 on the magnetic anisotropy, electrical structure and microstructure of CoFeB/MgO films.JOURNAL OF ALLOYS AND COMPOUNDS,725,425-432.
MLA	Zhang, P,et al."The effect of HfO2 on the magnetic anisotropy, electrical structure and microstructure of CoFeB/MgO films".JOURNAL OF ALLOYS AND COMPOUNDS 725(2017):425-432.