2001 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 / メモリアル / 磁化状態 / 漏洩磁束 / 情報記録層 / 環状メモリアル / 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)閉磁路構造を有する環状のメモリセルについて検討を行った。厚さ10nmのNi-20at%Feからなる直径1-2μmの円形の環状メモリセルでは、磁気光学効果測定装置および磁気力顕微鏡による磁化状態の観察により、磁化が円周に沿って還流し、環状メモリセルの外部には磁束が漏洩しないことがわかった。上記の円形環状メモリセルでは、磁束が漏洩しないため、メモリセルを極めて高密度に配列しても、メモリセル間の情報の干渉がなく、記録状態を安定に保つことができる。 (2)四角形および三角形の環状メモリセルでは、複雑な磁区構造となり、メモリセルの外部に磁束が漏洩する。このことから、超高密度配列に適したメモリセル形状は円形の環状であることが明らかになった。 (3)0.5μm×0.5μmから2μm×2μmのサイズの正方形メモリセルおよび0.5μmX1.0μmの長方形メモリセルの磁化状態を磁気力顕微鏡を用いて観察した。従来型のNi20at%Fe単層膜情報記憶磁性層は、面内還流磁区構造となり情報を失うのに対して、本研究で提案した基本構造であるNi-Fe/Hf/Ni-Fe積層膜情報記憶磁性層は、2層の磁性層の膜厚方向に磁化が還流し、面内方向には還流磁区構造とならずに情報を安定に保持することができることを明らかにした。

Research Products
(14 results)

All Other

All Publications (14 results)

[Publications] Ryoichi Nakatani, Masahiko Yamamoto, Hirotaka Yakame, Yasuhiro Kamada, Yoshio Kawamura: "Uniaxial magnetic anisotropy of Ni-Fe films exchange-coupled with Fe dotarrays"J.Magn.& Magn. Mater. (印刷中).
[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"J.Trans.Magn.Soc.Japan.. 2・2(印刷中). (2002)
[Publications] Ryoichi Nakatani, Takayuki Kusano, Masahiko Yamamoto: "Magnetic and electric properties of C/Mn/C/Si multilayers"4th International Symposium on Metallic Multilayers. 291 (2001)
[Publications] Yasuhiro Kamada, Yoshitaka Hitomi, Toshiki Kingetsu, Masahiko Yamamoto: "In situ observation of epitaxial growth of [Au/Co/Cu] and [Cu/Co/Au] superlattices and their magnetic interface anisotropies"J.Appl.Phys.. 90・10. 5104-5110 (2001)
[Publications] Ryoichi Nakatani, Hirotaka Yakame, Masahiko Yamamoto, Yasuhiro Kamada, Yoshio Kawamura: "Magnetic anisotropy of Ni-Fe films induced by overlying Fe dot-arrays"4th International Symposium on Metallic Multilayers. 54 (2001)
[Publications] Toshiki Kingetsu, Masahiko Yamamoto: "Epitaxial growth of short-period metallic superlattices for soft X-ray mirrors"Oyobuturi. 70. 428-432 (2001)
[Publications] Gyu Bong Cho, Yasuhiro Kamada, Masahiko Yamamoto: "Studies of self-organized steps and terraces in inclined SrTiO_3 (001)substrate"Jpn.J.Appl.Phys.. 40・7A. 4666-4671 (2001)
[Publications] Toshiki Kingetsn, Yasuhiro Kamada, Masahiko Yamamoto: "Epitaxial growth of binary and ternary metallic strained superlattices and their magnetic properties"Sci.Tech.Adv.Mat.. 2. 331-347 (2001)
[Publications] Yasuhiro Kamada, Akihiro Itoh, Masahiko Yamamoto: "Magnetic properties of amorphous Fe/La and BCC-Fe/La multilayers"Proc.of 4th Pacific Rim Intern.Conf.on Advanced Mat.and Processing. 127-130 (2001)
[Publications] Yasuhiro Kamada, Daisuke Takama, Akihiro Itoh, Hiroyuki Naka, Masahiko Yamamoto: "Towards fabrication of new functional muitilayers by hydrogenation"Proc.of 4th Pacific Rim Intern.Conf.on Advanced Mat.and Processing. 425-428 (2001)
[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Epitaxial Growth and magnetic anisotropies of binary and ternary metallic strained superlattices"J.Magn.& Magn.Mater.. 239・1-3. 262-264 (2002)
[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Interface structure of metallic strained epitaxially superlattices"Proc.of 4th Pacific Rim Intern.Conf.on Advanced Mat.and Processing. 721-724 (2001)
[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Structure and magnetic properties of metallic strained superlattices"J.Trans.Magn.Soc.Japan.. 2・2(印刷中). (2002)
[Publications] Toshiki Kingetsu, Masahiko Yamamoto: "Growth of short-period epitaxial superlattices for X-ray multilayer mirrors"Surface Science Report. 45(印刷中). (2002)

2001 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, Hirotaka Yakame, Yasuhiro Kamada, Yoshio Kawamura: "Uniaxial magnetic anisotropy of Ni-Fe films exchange-coupled with Fe dotarrays"J.Magn.& Magn. Mater. (印刷中).

[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"J.Trans.Magn.Soc.Japan.. 2・2(印刷中). (2002)

[Publications] Ryoichi Nakatani, Takayuki Kusano, Masahiko Yamamoto: "Magnetic and electric properties of C/Mn/C/Si multilayers"4th International Symposium on Metallic Multilayers. 291 (2001)

[Publications] Yasuhiro Kamada, Yoshitaka Hitomi, Toshiki Kingetsu, Masahiko Yamamoto: "In situ observation of epitaxial growth of [Au/Co/Cu] and [Cu/Co/Au] superlattices and their magnetic interface anisotropies"J.Appl.Phys.. 90・10. 5104-5110 (2001)

[Publications] Ryoichi Nakatani, Hirotaka Yakame, Masahiko Yamamoto, Yasuhiro Kamada, Yoshio Kawamura: "Magnetic anisotropy of Ni-Fe films induced by overlying Fe dot-arrays"4th International Symposium on Metallic Multilayers. 54 (2001)

[Publications] Toshiki Kingetsu, Masahiko Yamamoto: "Epitaxial growth of short-period metallic superlattices for soft X-ray mirrors"Oyobuturi. 70. 428-432 (2001)

[Publications] Gyu Bong Cho, Yasuhiro Kamada, Masahiko Yamamoto: "Studies of self-organized steps and terraces in inclined SrTiO_3 (001)substrate"Jpn.J.Appl.Phys.. 40・7A. 4666-4671 (2001)

[Publications] Toshiki Kingetsn, Yasuhiro Kamada, Masahiko Yamamoto: "Epitaxial growth of binary and ternary metallic strained superlattices and their magnetic properties"Sci.Tech.Adv.Mat.. 2. 331-347 (2001)

[Publications] Yasuhiro Kamada, Akihiro Itoh, Masahiko Yamamoto: "Magnetic properties of amorphous Fe/La and BCC-Fe/La multilayers"Proc.of 4th Pacific Rim Intern.Conf.on Advanced Mat.and Processing. 127-130 (2001)

[Publications] Yasuhiro Kamada, Daisuke Takama, Akihiro Itoh, Hiroyuki Naka, Masahiko Yamamoto: "Towards fabrication of new functional muitilayers by hydrogenation"Proc.of 4th Pacific Rim Intern.Conf.on Advanced Mat.and Processing. 425-428 (2001)

[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Epitaxial Growth and magnetic anisotropies of binary and ternary metallic strained superlattices"J.Magn.& Magn.Mater.. 239・1-3. 262-264 (2002)

[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Interface structure of metallic strained epitaxially superlattices"Proc.of 4th Pacific Rim Intern.Conf.on Advanced Mat.and Processing. 721-724 (2001)

[Publications] Toshiki Kingetsu, Yasuhiro Kamada, Masahiko Yamamoto: "Structure and magnetic properties of metallic strained superlattices"J.Trans.Magn.Soc.Japan.. 2・2(印刷中). (2002)

[Publications] Toshiki Kingetsu, Masahiko Yamamoto: "Growth of short-period epitaxial superlattices for X-ray multilayer mirrors"Surface Science Report. 45(印刷中). (2002)

中谷亮一大阪大学, 大学院・工学研究科, 助教授 (60314374)