Magnetic tunnel junctions with doubly-plasma oxidized AlOx insulation layer

Y. M. Lee; O. Song; C. S. Yoon; C. K. Kim; Y. Ando; H. Kubota; T. Miyazaki

doi:10.1016/S0026-2692(03)00138-1

Magnetic tunnel junctions with doubly-plasma oxidized AlO_x insulation layer

Y. M. Lee, O. Song, C. S. Yoon, C. K. Kim, Y. Ando, H. Kubota, T. Miyazaki

Department of Materials Science and Engineering

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

Abstract

Magnetic tunnel junctions (MTJ), with the tunnel barrier plasma oxidized in two steps, were fabricated in order to obtain structurally uniform AlO_x insulator. The doubly oxidized junctions exhibited the magnetoresistance (MR) ratio of 27-31% without showing any noticeable drop in the MR ratio even after oxidation time was extended well beyond the optimal oxidation time for the normal junctions. Transmission electron microscopy of the junctions confirmed that the AlO_x thickness was thinner for the doubly oxidized junctions compared to the singly oxidized MTJ. X-ray photoelectron spectroscopy of the doubly oxidized junction also strongly suggested that the initial oxide layer prevents the over-oxidation of the bottom electrode. The AlO_x tunnel barrier oxidized in two steps improved the junction performance and widened the processing window.

Original language	English
Pages (from-to)	805-808
Number of pages	4
Journal	Microelectronics Journal
Volume	34
Issue number	9
DOIs	https://doi.org/10.1016/S0026-2692(03)00138-1
State	Published - Sep 2003

Keywords

A1Ox tunnel barrier
Doubly oxidation
Inductively coupled plasma
Magnetic tunnel junction
Magnetoresistance ratio
Plasma oxidation

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10.1016/S0026-2692(03)00138-1

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title = "Magnetic tunnel junctions with doubly-plasma oxidized AlOx insulation layer",

abstract = "Magnetic tunnel junctions (MTJ), with the tunnel barrier plasma oxidized in two steps, were fabricated in order to obtain structurally uniform AlOx insulator. The doubly oxidized junctions exhibited the magnetoresistance (MR) ratio of 27-31% without showing any noticeable drop in the MR ratio even after oxidation time was extended well beyond the optimal oxidation time for the normal junctions. Transmission electron microscopy of the junctions confirmed that the AlOx thickness was thinner for the doubly oxidized junctions compared to the singly oxidized MTJ. X-ray photoelectron spectroscopy of the doubly oxidized junction also strongly suggested that the initial oxide layer prevents the over-oxidation of the bottom electrode. The AlOx tunnel barrier oxidized in two steps improved the junction performance and widened the processing window.",

keywords = "A1Ox tunnel barrier, Doubly oxidation, Inductively coupled plasma, Magnetic tunnel junction, Magnetoresistance ratio, Plasma oxidation",

author = "Lee, {Y. M.} and O. Song and Yoon, {C. S.} and Kim, {C. K.} and Y. Ando and H. Kubota and T. Miyazaki",

year = "2003",

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doi = "10.1016/S0026-2692(03)00138-1",

language = "English",

volume = "34",

pages = "805--808",

journal = "Microelectronics Journal",

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TY - JOUR

T1 - Magnetic tunnel junctions with doubly-plasma oxidized AlOx insulation layer

AU - Lee, Y. M.

AU - Song, O.

AU - Yoon, C. S.

AU - Kim, C. K.

AU - Ando, Y.

AU - Kubota, H.

AU - Miyazaki, T.

PY - 2003/9

Y1 - 2003/9

N2 - Magnetic tunnel junctions (MTJ), with the tunnel barrier plasma oxidized in two steps, were fabricated in order to obtain structurally uniform AlOx insulator. The doubly oxidized junctions exhibited the magnetoresistance (MR) ratio of 27-31% without showing any noticeable drop in the MR ratio even after oxidation time was extended well beyond the optimal oxidation time for the normal junctions. Transmission electron microscopy of the junctions confirmed that the AlOx thickness was thinner for the doubly oxidized junctions compared to the singly oxidized MTJ. X-ray photoelectron spectroscopy of the doubly oxidized junction also strongly suggested that the initial oxide layer prevents the over-oxidation of the bottom electrode. The AlOx tunnel barrier oxidized in two steps improved the junction performance and widened the processing window.

AB - Magnetic tunnel junctions (MTJ), with the tunnel barrier plasma oxidized in two steps, were fabricated in order to obtain structurally uniform AlOx insulator. The doubly oxidized junctions exhibited the magnetoresistance (MR) ratio of 27-31% without showing any noticeable drop in the MR ratio even after oxidation time was extended well beyond the optimal oxidation time for the normal junctions. Transmission electron microscopy of the junctions confirmed that the AlOx thickness was thinner for the doubly oxidized junctions compared to the singly oxidized MTJ. X-ray photoelectron spectroscopy of the doubly oxidized junction also strongly suggested that the initial oxide layer prevents the over-oxidation of the bottom electrode. The AlOx tunnel barrier oxidized in two steps improved the junction performance and widened the processing window.

KW - A1Ox tunnel barrier

KW - Doubly oxidation

KW - Inductively coupled plasma

KW - Magnetic tunnel junction

KW - Magnetoresistance ratio

KW - Plasma oxidation

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U2 - 10.1016/S0026-2692(03)00138-1

DO - 10.1016/S0026-2692(03)00138-1

M3 - Article

AN - SCOPUS:0038486982

SN - 0026-2692

VL - 34

SP - 805

EP - 808

JO - Microelectronics Journal

JF - Microelectronics Journal

IS - 9

ER -

Magnetic tunnel junctions with doubly-plasma oxidized AlO_x insulation layer

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Keywords

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