2002 Fiscal Year Annual Research Report

超高集積磁性メモリセル

Research Project

Project/Area Number	12450013
Research Institution	Osaka University
Principal Investigator	中谷亮一大阪大学, 大学院・工学研究科, 助教授 (60314374)
Co-Investigator(Kenkyū-buntansha)	遠藤恭大阪大学, 大学院・工学研究科, 助手 (50335379) 山本雅彦大阪大学, 大学院・工学研究科, 教授 (30029160)
Keywords	情報記憶デバイス / MRAM / メモリセル / 磁化状態 / 漏洩磁束 / 情報記録層 / 環状メモリセル / 還流磁区
Research Abstract	新世代の情報記憶メモリであるMRAM(Magnetic Random Access Memory)の記憶容量を大きくするためのブレークスルーを発見することを目的として、サブミクロンオーダー以下の大きさを有するメモリセルの磁気的特性および磁化状態について評価を行った。 (1)300nm×600nmから500nm×1000nmのサイズの長方形のNi-Fe(5nm)/Hf(5nm)およびNi-Fe(5nm)/Hf(2nm)/Ni-Fe(5nm)/Hf(5nm)メモリセルを形成し、磁化状態を磁気力顕微鏡を用いて観察した。従来のNi-Fe/Hfセルと比較して、本研究で提案した基本構造であるNi-Fe/Hf/Ni-Fe/Hf積層セルでは、2層の磁性層の膜厚方向に磁化が還流するため、低い磁界で記録状態を書き換えることができることを明らかにした。 (2)50nm×100nmから500nm×1000nmのサイズの長方形メモリセルに対するマイクロマグネティクス・シミュレーションにより、従来のNi-Fe/Hfセルと比較して、本研究で提案した基本構造であるNi-Fe/Hf/Ni-Fe/Hf積層セルでは、1/2程度の磁界で情報を書き換えることができることを明らかにした。 (3)閉磁路構造を有するリング状のメモリセルに対する記録方法について検討を行った。従来の構造のメモリセルでは、膜面垂直方向に電流を流すことにより磁界を発生しなければ、記録を行うことができなかった。これに対し、厚さ5-20nmのNi-20at%Feからなる直径500-1000nmの円形のリング状のメモリセルの一部を削り、磁束を通しにくい構造にすることにより、面内の電流による面内磁界により、記録可能となった。

Research Products
(14 results)

All Other

All Publications (14 results)

[Publications] Ryoichi Nakatani, Masahiko Yamamoto: "Magnetization Reversal with In-Plane Magnetic Field Asymmetric Ring Dots"Jpn.J.Appl.Phys.. 42・1. 100-101 (2003)
[Publications] Ryoichi Nakatani, Noritsugu Takahashi, Tetsuo Yoshida, Masahiko Yamamoto: "Magnetic States and Magnetization processes of Ni-Fe/Hf Annular Dots as Candidates of Non-Volatile Memory Cells"Jpn.J.Appl.Phys.. 41・12. 7359-7366 (2002)
[Publications] Ryoichi Nakatani, Takayuki Kusano, Hirotaka Yakame, Masahiko Yamamoto: "Magnetic and Electric Properties in C/Mn/C/Si Multilayers"Jpn.J.Appl.Phys.. 41・10. 5978-5981 (2002)
[Publications] Gyu Bong Cho, Masahiko Yamamoto, Yasuhiro Kamada: "Morphology of Fe Film Grown on Self-Organized SrTiO_3 (001) Substrate with Inclined Angle"Jpn.J.Appl.Phys.. 41・9. 5713-5718 (2002)
[Publications] Yu Shiratsuchi, Masahiko Yamamoto, Yasuhiro Kamada: "Surface Structure of Self-Organized Sapphire (0001) Substrates with Various Inclined Angle"Jpn.J.Appl.Phys.. 41・9. 5719-5725 (2002)
[Publications] Ryoichi Nakatani, Hirotaka Yakame, Yasushi Endo, Masahiko Yamamoto: "Magnetic Properties in Mn/Si-O/Si(100)-substrate Systems and Mn/Si-O/Si Trilayers"Jpn.J.Appl.Phys.. 42(印刷中). (2003)
[Publications] Yasuhiro Kamada, Akihiro Itoh, Daisuke Takama, Masahiko Yamamoto: "Effects of Hydrogenation on Structure, Transport and Magnetic Properties of the Multilayers Composed of Transition Metals and Rare-Earth Metals"Trans.Mag.Soc.Jpn.. 2・2. 69-75 (2002)
[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Structure and Magnetic Properties of Metallic Strained Superlattices"J.Magn.Soc.Jpn.. 26・4. 181-187 (2002)
[Publications] Ryoichi Nakatani, Noritsugu Takahashi, Hana Asoh, Yoshio Kawamura, Masahiko Yamamoto: "Fabrication of Ring Dot Arrays as a Candidate of Memory Cells"17th International Colloquium on Magnetic Films and Surfaces. 178-179 (2002)
[Publications] Ryoichi Nakatani, Takayuki Kusano, Hirotaka Yakame, Hideo Hoshiyama, Masahiko Yamamoto: "Ferromagnetism in Multilayers Including Mn Layers"17th International Colloquium on Magnetic Films and Surfaces. 290-291 (2002)
[Publications] Yasuhiro Kamada, Akihiro Itoh, Daisuke Takama, Masahiko Yamamoto: "Effects of Hydrogenation on Structure, Transport and Magnetic Properties of Multilayers Composed of Transition Metals and Rare-Earth Metals"17th International Colloquium on Magnetic Films and Surfaces. 386-387 (2002)
[Publications] Gyu Bong Cho, Masahiko Yamamoto, Yasuhiro Kamada: "Shape-Induced Anisotropy in Fe Films Grown on Inclined StTiO_3 (001) Substrate Made by the Self-Organization Phenomena"17th International Colloquium on Magnetic Films and Surfaces. 36-37 (2002)
[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Ternary Metallic Strained Superlattices"17th International Colloquium on Magnetic Films and Surfaces. 234-235 (2002)
[Publications] Masahiko Yamamoto, Naoto Sumida, Hitoshi Tampo: "Crossectional TEM Observation of Metallic Superlattices Co/Pt with Perpendicular Magnetization"Practical electron microscopy and its application to materials. 216 (2002)

2002 Fiscal Year Annual Research Report

超高集積磁性メモリセル

Principal Investigator

中谷 亮一 大阪大学, 大学院・工学研究科, 助教授 (60314374)

Research Products

[Publications] Ryoichi Nakatani, Masahiko Yamamoto: "Magnetization Reversal with In-Plane Magnetic Field Asymmetric Ring Dots"Jpn.J.Appl.Phys.. 42・1. 100-101 (2003)

[Publications] Ryoichi Nakatani, Noritsugu Takahashi, Tetsuo Yoshida, Masahiko Yamamoto: "Magnetic States and Magnetization processes of Ni-Fe/Hf Annular Dots as Candidates of Non-Volatile Memory Cells"Jpn.J.Appl.Phys.. 41・12. 7359-7366 (2002)

[Publications] Ryoichi Nakatani, Takayuki Kusano, Hirotaka Yakame, Masahiko Yamamoto: "Magnetic and Electric Properties in C/Mn/C/Si Multilayers"Jpn.J.Appl.Phys.. 41・10. 5978-5981 (2002)

[Publications] Gyu Bong Cho, Masahiko Yamamoto, Yasuhiro Kamada: "Morphology of Fe Film Grown on Self-Organized SrTiO_3 (001) Substrate with Inclined Angle"Jpn.J.Appl.Phys.. 41・9. 5713-5718 (2002)

[Publications] Yu Shiratsuchi, Masahiko Yamamoto, Yasuhiro Kamada: "Surface Structure of Self-Organized Sapphire (0001) Substrates with Various Inclined Angle"Jpn.J.Appl.Phys.. 41・9. 5719-5725 (2002)

[Publications] Ryoichi Nakatani, Hirotaka Yakame, Yasushi Endo, Masahiko Yamamoto: "Magnetic Properties in Mn/Si-O/Si(100)-substrate Systems and Mn/Si-O/Si Trilayers"Jpn.J.Appl.Phys.. 42(印刷中). (2003)

[Publications] Yasuhiro Kamada, Akihiro Itoh, Daisuke Takama, Masahiko Yamamoto: "Effects of Hydrogenation on Structure, Transport and Magnetic Properties of the Multilayers Composed of Transition Metals and Rare-Earth Metals"Trans.Mag.Soc.Jpn.. 2・2. 69-75 (2002)

[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Structure and Magnetic Properties of Metallic Strained Superlattices"J.Magn.Soc.Jpn.. 26・4. 181-187 (2002)

[Publications] Ryoichi Nakatani, Noritsugu Takahashi, Hana Asoh, Yoshio Kawamura, Masahiko Yamamoto: "Fabrication of Ring Dot Arrays as a Candidate of Memory Cells"17th International Colloquium on Magnetic Films and Surfaces. 178-179 (2002)

[Publications] Ryoichi Nakatani, Takayuki Kusano, Hirotaka Yakame, Hideo Hoshiyama, Masahiko Yamamoto: "Ferromagnetism in Multilayers Including Mn Layers"17th International Colloquium on Magnetic Films and Surfaces. 290-291 (2002)

[Publications] Yasuhiro Kamada, Akihiro Itoh, Daisuke Takama, Masahiko Yamamoto: "Effects of Hydrogenation on Structure, Transport and Magnetic Properties of Multilayers Composed of Transition Metals and Rare-Earth Metals"17th International Colloquium on Magnetic Films and Surfaces. 386-387 (2002)

[Publications] Gyu Bong Cho, Masahiko Yamamoto, Yasuhiro Kamada: "Shape-Induced Anisotropy in Fe Films Grown on Inclined StTiO_3 (001) Substrate Made by the Self-Organization Phenomena"17th International Colloquium on Magnetic Films and Surfaces. 36-37 (2002)

[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Ternary Metallic Strained Superlattices"17th International Colloquium on Magnetic Films and Surfaces. 234-235 (2002)

[Publications] Masahiko Yamamoto, Naoto Sumida, Hitoshi Tampo: "Crossectional TEM Observation of Metallic Superlattices Co/Pt with Perpendicular Magnetization"Practical electron microscopy and its application to materials. 216 (2002)

中谷亮一大阪大学, 大学院・工学研究科, 助教授 (60314374)