Crystallization characteristics of a middle CoFeB layer in a double MgO barrier magnetic tunnel junction

被引：5
作者：
Lee, Seungkyo [1 ]
Kim, Kwangseok [2 ]
Hwang, Injun [2 ]
Cho, B. K. [1 ]
机构：
[1] Gwangju Inst Sci & Technol, Sch Mat Sci & Engn, Kwangju 500712, South Korea
[2] Samsung Adv Inst Technol, Yongin 446712, Gyeonggi Do, South Korea
来源：
CURRENT APPLIED PHYSICS | 2015年 / 15卷 / 01期
基金：
新加坡国家研究基金会;
关键词：
Magnetic tunnel junction; Crystallization; Magnetoresistance;
D O I：
10.1016/j.cap.2014.10.028
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
The crystallization characteristics of a middle CoFeB free layer in a magnetic tunnel junction (MTJ) with double MgO barriers were investigated by tunneling magnetoresistance (TMR) measurements of patterned cells across an 8-inch wafer. The MTJ structure was designed to have two CoFeB free layers and one bottom pinned layer, separated by MgO tunnel barriers. The observed resistance showed three types of TMR curves depending on the crystallization of the middle CoFeB layer. From the analysis of TMR curves, coherent crystallization of the middle CoFeB layer with the top and bottom MgO barriers was found to occur non-uniformly: About 80% of the MTJ cells in the wafer exhibited coherent crystallization of the middle CoFeB layers with the bottom MgO tunnel barrier, while others had coherent crystallization with the top MgO tunnel barrier or both barriers. This non-uniform crystallization of the middle CoFeB layer in a double MTJ was also clearly observed in tunneling electron microscopy images. Thus, control of the crystallization of the middle CoFeB layer is important for optimizing the MTJ with double MgO barriers, and especially for the fabrication of double barrier MTJ on a large area substrate. (C) 2014 Elsevier B.V. All rights reserved.
引用
收藏
页码：38 / 41
页数：4
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