Patents by Inventor Masayuki Sagoi
Masayuki Sagoi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6707711Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.Type: GrantFiled: February 4, 2003Date of Patent: March 16, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
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Publication number: 20030197984Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.Type: ApplicationFiled: May 23, 2003Publication date: October 23, 2003Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
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Patent number: 6611405Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.Type: GrantFiled: September 14, 2000Date of Patent: August 26, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
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Patent number: 6605836Abstract: Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The magnetoresistance effect devices may be used in a magnetic memory apparatus, such as a random access memory, a personal digital assistance, a magnetic reproducing head, and a magnetic information reproducing apparatus.Type: GrantFiled: March 15, 2002Date of Patent: August 12, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Tatsuya Kishi, Shigeki Takahashi, Kentaro Nakajima, Minoru Amano, Masayuki Sagoi, Yoshiaki Saito
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Publication number: 20030137870Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.Type: ApplicationFiled: February 4, 2003Publication date: July 24, 2003Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
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Patent number: 6590803Abstract: A magnetic memory device includes a plurality of magnetoresistive elements arranged on a first plane in a matrix form, a plurality of first writing lines which are arranged on a second plane different from the first plane adjacent to the magnetoresistive elements, a first address decoder which selects a desired one from the plurality of first writing lines, a plurality of second writing lines crossing the plurality of first writing lines on a third plane different from the second plane and having parts adjacent to the plurality of magnetoresistive elements on the second plane and parallel to the plurality of first writing lines, and a second address decoder which selects a desired one from the plurality of second writing lines.Type: GrantFiled: March 22, 2002Date of Patent: July 8, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiaki Saito, Kentaro Nakajima, Masayuki Sagoi, Minoru Amano, Shigeki Takahashi, Tatsuya Kishi
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Patent number: 6556473Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.Type: GrantFiled: July 26, 2001Date of Patent: April 29, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
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Publication number: 20020191451Abstract: A magnetoresistance effect devices having a magnetization free layer free to rotate in an applied magnetic field. The magnetization free layer may include first and second ferromagnetic material layers with a nonmagnetic material layer disposed between the two ferromagnetic material layers. Those ferromagnetic materials are antiferromagnetically coupled with each other at a magnetic coupling field J (−3 [kOe]≦J<0 [kOe]) or ferromagnetically coupled with each other. Alternatively, the magnetization free film includes a first ferromagnetic material layer including a center region having a first magnetization and edge regions having a second magnetization different from the first magnetization and a second ferromagnetic material layer including a center region having a third magnetization parallel to the first magnetization and edge regions having a fourth magnetization different from the third magnetization.Type: ApplicationFiled: March 22, 2002Publication date: December 19, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tatsuya Kishi, Minoru Amano, Yoshiaki Saito, Shigeki Takahashi, Kentaro Nakajima, Masayuki Sagoi
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Publication number: 20020159203Abstract: There is provided a magnetoresistance effect element including a first pinned ferromagnetic layer, a second pinned ferromagnetic layer facing the first pinned ferromagnetic layer, surface regions of the first and second pinned ferromagnetic layer facing each other being different from each other in composition, a free ferromagnetic layer intervening between the first and second pinned ferromagnetic layers, a first tunnel barrier layer intervening between the first pinned ferromagnetic layer and the free ferromagnetic layer, and a second tunnel barrier layer intervening between the second pinned ferromagnetic layer and the free ferromagnetic layer.Type: ApplicationFiled: March 11, 2002Publication date: October 31, 2002Inventors: Yoshiaki Saito, Masayuki Sagoi, Minoru Amano, Kentaro Nakajima, Shigeki Takahashi, Tatsuya Kishi
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Patent number: 6473336Abstract: A magnetic memory device comprises a memory cell assembled by first and second tunnel junction portions and a switch, each of the first and second tunnel junction portions being formed of a stack of a pinned layer in which a magnetization direction is fixed and a record layer in which a magnetization direction changes depending on an external magnetic field. A first data line is connected to a first end of the first tunnel junction portion. A second data line is connected to the first end of the second tunnel junction portion. A bit line is connected to the second end of the first tunnel junction portion and the second end of the second tunnel junction portion via the switch.Type: GrantFiled: December 14, 2000Date of Patent: October 29, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Kentaro Nakajima, Koichiro Inomata, Yoshiaki Saito, Masayuki Sagoi
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Publication number: 20020141232Abstract: A magnetic memory device includes a plurality of magnetoresistive elements arranged on a first plane in a matrix form, a plurality of first writing lines which are arranged on a second plane different from the first plane adjacent to the magnetoresistive elements, a first address decoder which selects a desired one from the plurality of first writing lines, a plurality of second writing lines crossing the plurality of first writing lines on a third plane different from the second plane and having parts adjacent to the plurality of magnetoresistive elements on the second plane and parallel to the plurality of first writing lines, and a second address decoder which selects a desired one from the plurality of second writing lines.Type: ApplicationFiled: March 22, 2002Publication date: October 3, 2002Inventors: Yoshiaki Saito, Kentaro Nakajima, Masayuki Sagoi, Minoru Amano, Shigeki Takahashi, Tatsuya Kishi
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Publication number: 20020130339Abstract: Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The manufacturing method uses two linear mask patterns intersecting with each other to form sharp corners of a ferromagnetic tunnel junction. An electron beam (EB) drawing may be used to form the S-shape plane.Type: ApplicationFiled: March 15, 2002Publication date: September 19, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tatsuya Kishi, Shigeki Takahashi, Kentaro Nakajima, Minoru Amano, Masayuki Sagoi, Yoshiaki Saito
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Publication number: 20020034094Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.Type: ApplicationFiled: July 26, 2001Publication date: March 21, 2002Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
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Publication number: 20020006058Abstract: A magnetic memory device comprises a memory cell assembled by first and second tunnel junction portions and a switch, each of the first and second tunnel junction portions being formed of a stack of a pinned layer in which a magnetization direction is fixed and a record layer in which a magnetization direction changes depending on an external magnetic field. A first data line is connected to a first end of the first tunnel junction portion. A second data line is connected to the first end of the second tunnel junction portion. A bit line is connected to the second end of the first tunnel junction portion and the second end of the second tunnel junction portion via the switch.Type: ApplicationFiled: December 14, 2000Publication date: January 17, 2002Inventors: Kentaro Nakajima, Koichiro Inomata, Yoshiaki Saito, Masayuki Sagoi
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Patent number: 5126320Abstract: A method is disclosed which comprises setting a substrate within a mixed gas atmosphere containing 0.1 to 5% of oxygen gas and a balance as an inert gas, and sputtering a target member containing Ln, M, Cu and O within that atmosphere to obtain an oxygen-deficient perovskite type oxide superconducting thin-film of substantially Ln:M:Cu:O=1:2:3:(7-.delta.), where Ln represents at least one element selected from the rare earth elements and M represents at least one element selected from the group consisting of Ba, Sr, and Ca. The oxide superconducting thin-film of that composition ratio has a critical temperature of over 77K.Type: GrantFiled: June 26, 1991Date of Patent: June 30, 1992Assignee: Kabushiki Kaisha ToshibaInventors: Tadao Miura, Yoshiaki Terashima, Akio Hori, Masayuki Sagoi
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Patent number: 4801481Abstract: A perpendicular magnetic recording floppy disk comprises a flexible plastic film substrate, a first magnetic recording layer formed on one side of the plastic film substrate and having an axis of easy magnetization in a direction perpendicular to the one side of the plastic film substrate, and a second magnetic recording layer formed on the other side of the plastic film substrate and having an axis of easy magnetization in a direction perpendicular to the above-mentioned other side of the plastic film substrate. The second magnetic recording layer has a thickness greater than a thickness of the first magnetic recording layer.Type: GrantFiled: June 17, 1983Date of Patent: January 31, 1989Assignee: Tokyo Shibaura Denki Kabushiki KaishaInventors: Masayuki Sagoi, Reiji Nishikawa
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Patent number: 4761334Abstract: A magnetic recording medium in which a silicon nitride film is formed on a magnetic recording layer having an axis of easy magnetization in the direction essentially perpendicular to its own layer surface. The magnetic recording layer is a metallic magnetic film such as a Co-Cr containing alloy. The silicon nitride film is preferably in a state in which the number of nitrogen atoms is less than four thirds of the number of silicon atoms. A lubricant layer such as a layer of fluorocarbon can be formed on the silicon nitride film.Type: GrantFiled: July 1, 1985Date of Patent: August 2, 1988Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Sagoi, Noritsugu Kawashima, Yoichiro Tanaka, Kunio Sekine
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Patent number: 4748073Abstract: A perpendicular magnetic floppy disk has a base layer on each side of which a recording layer is formed having an axis of easy magnetization in a direction perpendicular to its surface. A multilayered protective layer structure is provided on the recording layer. The protective layer structure includes double-stacked non-magnetic thin-film layer structures made of an Si-N-O-based film and silicon oxide film, respectively. The total thickness of the multilayered protective layer structure is smaller than 40 nanometers, which is thin enough to maximize an efficiency in perpendicular magnetic recording of data signal.Type: GrantFiled: June 26, 1986Date of Patent: May 31, 1988Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Sagoi, Yoichiro Tanaka
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Patent number: 4701374Abstract: A magnetic recording medium obtained by forming a Si-N-O system film on a magnetic recording layer with perpendicular axis of easy magnetization. The magnetic recording layer is a metallic magnetic film such as Co-Cr system alloy film. The oxygen content in the Si-N-O system film is selected preferably to show a maximum absorption of infrared radiation in the range above 830 cm.sup.-1 and below 1100 cm.sup.-1 of 1/.lambda. (.lambda. is the wavelength of the infrared radiation). Through formation of the Si-N-O system film, the magnetic recording medium can satisfy simultaneously both of the durability and the perpendicular magnetic recording characteristics.Type: GrantFiled: July 1, 1985Date of Patent: October 20, 1987Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Sagoi, Yoichiro Tanaka, Hiroki Nakamura
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Patent number: 4680197Abstract: A method of manufacturing a perpendicular magnetic recording floppy disk is disclosed. A first magnetic recording layer is formed by sputtering a perpendicularly magnetizable material on one side of a plastic film substrate. A second magnetic recording layer is formed by sputtering the perpendicularly magnetizable material on the other side of the plastic film substrate after forming the first magnetic recording layer. The second magnetic recording layer has a thickness greater than that of the first magnetic recording layer, when a curl of the first magnetic recording layer on the plastic film substrate, resulting from forming the first magnetic recording layer on the plastic film substrate, is to the outside. On the other hand, the second magnetic recording layer has a thickness lower than that of the first magnetic recording layer, when a curl of the first magnetic recording layer on the plastic film substrate is to the inside.Type: GrantFiled: December 2, 1985Date of Patent: July 14, 1987Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Sagoi, Reiji Nishikawa