CoFeB/MgO/CoFeB強磁性トンネル接合におけるMgO障壁層の結晶配向性制御および巨大トンネル磁気抵抗効果の導出

• 資料種別: 記事
• タイトル: CoFeB/MgO/CoFeB強磁性トンネル接合におけるMgO障壁層の結晶配向性制御および巨大トンネル磁気抵抗効果の導出
• 著者・編者: 芦澤 好人; 大山 博久; 須永 和晋 他
• 著者標目: 芦澤 好人; 大山 博久; 須永 和晋
• 並列タイトル等: Giant tunnel magnetoresistance effect derived by controlling crystallographic orientation of MgO barrier in CoFeB/MgO/CoFeB magnetic tunnel junctions
• タイトル（掲載誌）: 日本応用磁気学会誌
• 巻号年月日等（掲載誌）: 31(5) (通号 227) 2007
• 掲載巻: 31
• 掲載号: 5
• 掲載通号: 227
• 掲載ページ: 411～415
• 掲載年月日（W3CDTF）: 2007
• ISSN（掲載誌）: 0285-0192
• ISSN-L（掲載誌）: 0285-0192
• 出版事項（掲載誌）: 東京 : 日本磁気学会
• 出版地（国名コード）: JP
• 本文の言語コード: jpn
• 件名標目: magnetic tunnel junction; tunnel magnetoresistance; MgO; CoFeB; crystallographic orientation
• NDLC: ZM35
• 対象利用者: 一般
• コレクション（個別）: 国立国会図書館デジタルコレクション > 電子書籍・電子雑誌 > 学術機関 > 学協会; https://dl.ndl.go.jp/collections/B00043
• オンライン閲覧公開範囲: インターネット公開
• 遠隔複写可否（NDL）: 不可
• 所蔵機関: 国立国会図書館
• 請求記号: Z15-398
• 関連情報（URI）: http://dl.ndl.go.jp/info:ndljp/pid/10467632
• 関連情報（国立国会図書館永続的識別子）: info:ndljp/pid/10467632; http://dl.ndl.go.jp/info:ndljp/pid/10467632
• 連携機関・データベース: 国立国会図書館 : 国立国会図書館雑誌記事索引; https://ndlsearch.ndl.go.jp
• 書誌ID（NDLBibID）: 8934042; http://id.ndl.go.jp/bib/8934042
• 整理区分コード: 632

• 要約等: Crystallographic orientation of the MgO barrier in sputter-deposited CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJs) and its effect on tunnel magnetoresistance (TMR) were investigated. The degree of MgO(001) orientation was estimated with the integral intensity ratio (<i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎) of diffraction lines from MgO(200) and MgO(220) planes obtained in grazing incident x-ray diffraction profiles. The main results are stated as follows. (1) <i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎ ∼ 4, meaning the (001) orientation of MgO, is realized when the underlaid CoFeB maintains amorphous structure, meanwhile MgO on bcc(110)-oriented CoFe shows (111) orientation (<i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎ = 0). (2) The prevention of epitaxial growth on hcp(00.1)-oriented Ru layer is effective to maintain amorphous structure of CoFeB. (3) The achievable TMR ratio after high temperature (280 °C − 450 °C) annealing is mainly dominated by the MgO orientation and giant TMR ratio exceeding 200% is only obtained with <i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎ ≥ 3.4, while the resistance area product is independent of <i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎. (4) Thin Mg layer inserted between CoFeB layer and MgO barrier is effective to obtain bcc(001)-oriented crystallization of CoFeB after high temperature annealing and results in a giant TMR ratio, because of its role to avoid surface oxidization of underlying ferromagnetic electrode during the deposition of MgO barrier.
• DOI: 10.3379/jmsjmag.31.411
• オンライン閲覧公開範囲: インターネット公開
• 連携機関・データベース: 科学技術振興機構 : J-STAGE; http://www.jstage.jst.go.jp

• 要約等: Crystallographic orientation of the MgO barrier in sputter-deposited CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJs) and its effect on tunnel magnetoresistance (TMR) were investigated. The degree of MgO(001) orientation was estimated with the integral intensity ratio (<i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎) of diffraction lines from MgO(200) and MgO(220) planes obtained in grazing incident x-ray diffraction profiles. The main results are stated as follows. (1) <i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎ ∼ 4, meaning the (001) orientation of MgO, is realized when the underlaid CoFeB maintains amorphous structure, meanwhile MgO on bcc(110)-oriented CoFe shows (111) orientation (<i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎ = 0). (2) The prevention of epitaxial growth on hcp(00.1)-oriented Ru layer is effective to maintain amorphous structure of CoFeB. (3) The achievable TMR ratio after high temperature (280 °C − 450 °C) annealing is mainly dominated by the MgO orientation and giant TMR ratio exceeding 200% is only obtained with <i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎ ≥ 3.4, while the resistance area product is independent of <i>I</i>₍₂₀₀₎ /<i>I</i>₍₂₂₀₎. (4) Thin Mg layer inserted between CoFeB layer and MgO barrier is effective to obtain bcc(001)-oriented crystallization of CoFeB after high temperature annealing and results in a giant TMR ratio, because of its role to avoid surface oxidization of underlying ferromagnetic electrode during the deposition of MgO barrier.
• DOI: 10.3379/jmsjmag.31.411; https://doi.org/10.3379/jmsjmag.31.411
• 関連情報（URI）: http://id.ndl.go.jp/bib/8934042; https://ndlsearch.ndl.go.jp/books/R000000004-I8934042; https://dl.ndl.go.jp/pid/10467632; http://id.ndl.go.jp/digimeta/10467632; http://dl.ndl.go.jp/info:ndljp/pid/10467632
• 参照: Effects of boron composition on tunneling magnetoresistance ratio and microstructure of CoFeB/MgO/CoFeB pseudo-spin-valve magnetic tunnel junctions; https://cir.nii.ac.jp/crid/1360004233898249856; ＣｏＦｅＢ／ＭｇＯ／ＣｏＦｅＢ 強磁性トンネル接合膜の積層界面制御による障壁膜配向制御とトンネル磁気抵抗効果; https://cir.nii.ac.jp/crid/1390282680270513792; Si 基板上への(001)配向 MgO 薄膜の作製; https://cir.nii.ac.jp/crid/1390282681458927872
• 参照: Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriers; https://cir.nii.ac.jp/crid/1360855569296954112; 230% room-temperature magnetoresistance in CoFeB∕MgO∕CoFeB magnetic tunnel junctions; https://cir.nii.ac.jp/crid/1361137045762398464; Giant tunneling magnetoresistance effect in low-resistance CoFeB∕MgO(001)∕CoFeB magnetic tunnel junctions for read-head applications; https://cir.nii.ac.jp/crid/1361981468743444864; Giant tunnel magnetoresistance and high annealing stability in CoFeB∕MgO∕CoFeB magnetic tunnel junctions with synthetic pinned layer; https://cir.nii.ac.jp/crid/1361981469327115264; Giant tunneling magnetoresistance up to 410% at room temperature in fully epitaxial Co∕MgO∕Co magnetic tunnel junctions with bcc Co(001) electrodes; https://cir.nii.ac.jp/crid/1361981470726785280; Spin-dependent tunneling conductance of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="normal">Fe</mml:mi><mml:mi>|</mml:mi><mml:mi mathvariant="normal">MgO</mml:mi><mml:mi>|</mml:mi><mml:mi mathvariant="normal">Fe</mml:mi></mml:math>sandwiches; https://cir.nii.ac.jp/crid/1362262943315103744; Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctions; https://cir.nii.ac.jp/crid/1362262944607103744; Magnetoresistance measurement of unpatterned magnetic tunnel junction wafers by current-in-plane tunneling; https://cir.nii.ac.jp/crid/1363670320423833600; Characterization of growth and crystallization processes in CoFeB∕MgO∕CoFeB magnetic tunnel junction structure by reflective high-energy electron diffraction; https://cir.nii.ac.jp/crid/1363951793925866368; Large magnetoresistance in bcc<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Co</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Mg</mml:mi><mml:mi mathvariant="normal">O</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Co</mml:mi></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Fe</mml:mi><mml:mi mathvariant="normal">Co</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Mg</mml:mi><mml:mi mathvariant="normal">O</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Fe</mml:mi><mml:mi mathvariant="normal">Co</mml:mi></mml:mrow></mml:math>tunnel junctions; https://cir.nii.ac.jp/crid/1363951795515001856
• 連携機関・データベース: 国立情報学研究所 : CiNii Research; https://cir.nii.ac.jp/
• 提供元機関・データベース: Japan Link Center; https://japanlinkcenter.org/top; 雑誌記事索引データベース; https://ndlsearch.ndl.go.jp; Crossref; https://www.crossref.org; 国立国会図書館デジタルコレクション; https://dl.ndl.go.jp/ja; CiNii Articles
• 書誌ID（NDLBibID）: 8934042; http://id.ndl.go.jp/bib/8934042; 10467632; http://id.ndl.go.jp/bib/10467632
• NII論文ID: 110006381212; 130004479130