Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB

J. R. Rhee; J. Y. Hwang; S. S. Kim; M. Y. Kim; B. S. Chun; I. S. Yoo; B. S. Oh; Y. K. Kim; T. W. Kim; W. J. Park

doi:10.1109/TMAG.2005.855296

Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB

J. R. Rhee, J. Y. Hwang, S. S. Kim, M. Y. Kim, B. S. Chun, I. S. Yoo, B. S. Oh, Y. K. Kim, T. W. Kim, W. J. Park

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11 Citations (Scopus)

Abstract

Magnetic tunnel junctions (MTJs), which consisted of amorphous CoFeSiB layers, were investigated. The CoFeSiB layers were used to substitute for the traditionally used CoFe and/or NiFe layers with an emphasis given on understanding the effect of the amorphous free layer on the switching characteristics of the MTJs. CoFeSiB has a lower saturation magnetization (M_s : 560 emu/cm³) and a higher anisotropy constant (K_u : 2 800 erg/cm³) than CoFe and NiFe, respectively. An exchange coupling energy (J_ex) of -0.003 erg/cm² was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the Si-SiO₂-Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlO_x/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nanometers) MTJs structure, it was found that the size dependence of the switching field originated in the lower J_ex using the experimental and simulation results. The CoFeSiB synthetic antiferromagnet structures were proved to be beneficial for the switching characteristics such as reducing the coercivity (H_c) and increasing the sensitivity in micrometer size, even in submicrometer sized elements.

Original language	English
Pages (from-to)	2685-2687
Number of pages	3
Journal	IEEE Transactions on Magnetics
Volume	41
Issue number	10
DOIs	https://doi.org/10.1109/TMAG.2005.855296
Publication status	Published - 2005 Oct
Externally published	Yes

Bibliographical note

Funding Information:
This work was supported by the Korea Research Foundation Grant funded by the Korea Government (MOEHRD) (R06-2004-007-01 001-0), and by the Korea Ministry of Science and Technology under contract National Research Laboratory Program.

Keywords

Amorphous ferromagnet
CoFeSiB
Magnetic random access memory (MRAM)
Switching field
Synthetic antiferromagnet (SAF)
Tunneling magnetoresistance (TMR)

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

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10.1109/TMAG.2005.855296

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Rhee, J. R., Hwang, J. Y., Kim, S. S., Kim, M. Y., Chun, B. S., Yoo, I. S., Oh, B. S., Kim, Y. K., Kim, T. W., & Park, W. J. (2005). Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB. IEEE Transactions on Magnetics, 41(10), 2685-2687. https://doi.org/10.1109/TMAG.2005.855296

@article{b5e4ebbc38f94196a89d1c9c8a09a440,

title = "Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB",

abstract = "Magnetic tunnel junctions (MTJs), which consisted of amorphous CoFeSiB layers, were investigated. The CoFeSiB layers were used to substitute for the traditionally used CoFe and/or NiFe layers with an emphasis given on understanding the effect of the amorphous free layer on the switching characteristics of the MTJs. CoFeSiB has a lower saturation magnetization (Ms : 560 emu/cm3) and a higher anisotropy constant (Ku : 2 800 erg/cm3) than CoFe and NiFe, respectively. An exchange coupling energy (Jex) of -0.003 erg/cm2 was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the Si-SiO2-Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlOx/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nanometers) MTJs structure, it was found that the size dependence of the switching field originated in the lower Jex using the experimental and simulation results. The CoFeSiB synthetic antiferromagnet structures were proved to be beneficial for the switching characteristics such as reducing the coercivity (Hc) and increasing the sensitivity in micrometer size, even in submicrometer sized elements.",

keywords = "Amorphous ferromagnet, CoFeSiB, Magnetic random access memory (MRAM), Switching field, Synthetic antiferromagnet (SAF), Tunneling magnetoresistance (TMR)",

author = "Rhee, {J. R.} and Hwang, {J. Y.} and Kim, {S. S.} and Kim, {M. Y.} and Chun, {B. S.} and Yoo, {I. S.} and Oh, {B. S.} and Kim, {Y. K.} and Kim, {T. W.} and Park, {W. J.}",

note = "Funding Information: This work was supported by the Korea Research Foundation Grant funded by the Korea Government (MOEHRD) (R06-2004-007-01 001-0), and by the Korea Ministry of Science and Technology under contract National Research Laboratory Program.",

year = "2005",

month = oct,

doi = "10.1109/TMAG.2005.855296",

language = "English",

volume = "41",

pages = "2685--2687",

journal = "IEEE Transactions on Magnetics",

issn = "0018-9464",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

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T1 - Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB

AU - Rhee, J. R.

AU - Hwang, J. Y.

AU - Kim, S. S.

AU - Kim, M. Y.

AU - Chun, B. S.

AU - Yoo, I. S.

AU - Oh, B. S.

AU - Kim, Y. K.

AU - Kim, T. W.

AU - Park, W. J.

N1 - Funding Information: This work was supported by the Korea Research Foundation Grant funded by the Korea Government (MOEHRD) (R06-2004-007-01 001-0), and by the Korea Ministry of Science and Technology under contract National Research Laboratory Program.

PY - 2005/10

Y1 - 2005/10

N2 - Magnetic tunnel junctions (MTJs), which consisted of amorphous CoFeSiB layers, were investigated. The CoFeSiB layers were used to substitute for the traditionally used CoFe and/or NiFe layers with an emphasis given on understanding the effect of the amorphous free layer on the switching characteristics of the MTJs. CoFeSiB has a lower saturation magnetization (Ms : 560 emu/cm3) and a higher anisotropy constant (Ku : 2 800 erg/cm3) than CoFe and NiFe, respectively. An exchange coupling energy (Jex) of -0.003 erg/cm2 was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the Si-SiO2-Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlOx/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nanometers) MTJs structure, it was found that the size dependence of the switching field originated in the lower Jex using the experimental and simulation results. The CoFeSiB synthetic antiferromagnet structures were proved to be beneficial for the switching characteristics such as reducing the coercivity (Hc) and increasing the sensitivity in micrometer size, even in submicrometer sized elements.

AB - Magnetic tunnel junctions (MTJs), which consisted of amorphous CoFeSiB layers, were investigated. The CoFeSiB layers were used to substitute for the traditionally used CoFe and/or NiFe layers with an emphasis given on understanding the effect of the amorphous free layer on the switching characteristics of the MTJs. CoFeSiB has a lower saturation magnetization (Ms : 560 emu/cm3) and a higher anisotropy constant (Ku : 2 800 erg/cm3) than CoFe and NiFe, respectively. An exchange coupling energy (Jex) of -0.003 erg/cm2 was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the Si-SiO2-Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlOx/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nanometers) MTJs structure, it was found that the size dependence of the switching field originated in the lower Jex using the experimental and simulation results. The CoFeSiB synthetic antiferromagnet structures were proved to be beneficial for the switching characteristics such as reducing the coercivity (Hc) and increasing the sensitivity in micrometer size, even in submicrometer sized elements.

KW - Amorphous ferromagnet

KW - CoFeSiB

KW - Magnetic random access memory (MRAM)

KW - Switching field

KW - Synthetic antiferromagnet (SAF)

KW - Tunneling magnetoresistance (TMR)

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U2 - 10.1109/TMAG.2005.855296

DO - 10.1109/TMAG.2005.855296

M3 - Article

AN - SCOPUS:27744498823

SN - 0018-9464

VL - 41

SP - 2685

EP - 2687

JO - IEEE Transactions on Magnetics

JF - IEEE Transactions on Magnetics

IS - 10

ER -

Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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