Patents by Inventor Hiroaki Honjou
Hiroaki Honjou 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: 9478309Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.Type: GrantFiled: September 13, 2013Date of Patent: October 25, 2016Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
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Patent number: 9406869Abstract: A semiconductor device includes: a first magnetic layer (1) disposed on a flat substrate surface; a second magnetic layer (3) disposed above the first magnetic layer (1) and magnetically coupled to the first magnetic layer (1) by magnetostatic coupling or exchange coupling; and a third thin film layer (8) formed between the first magnetic layer (1) and the second magnetic layer (3), the third thin film layer (8) having such a thickness as to avoid inhibiting the magnetic coupling between the first magnetic layer (1) and the second magnetic layer (3).Type: GrantFiled: April 24, 2013Date of Patent: August 2, 2016Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Hiroaki Honjou, Keizo Kinoshita, Hideo Ohno
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Publication number: 20150248939Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.Type: ApplicationFiled: September 13, 2013Publication date: September 3, 2015Applicants: NEC Corporation, Tohoku UniversityInventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
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Publication number: 20150200354Abstract: A semiconductor device includes: a first magnetic layer (1) disposed on a flat substrate surface; a second magnetic layer (3) disposed above the first magnetic layer (1) and magnetically coupled to the first magnetic layer (1) by magnetostatic coupling or exchange coupling; and a third thin film layer (8) formed between the first magnetic layer (1) and the second magnetic layer (3), the third thin film layer (8) having such a thickness as to avoid inhibiting the magnetic coupling between the first magnetic layer (1) and the second magnetic layer (3).Type: ApplicationFiled: April 24, 2013Publication date: July 16, 2015Applicants: TOHOKU UNIVERSITY, NEC CORPORATIONInventors: Hiroaki Honjou, Keizo Kinoshita, Hideo Ohno
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Patent number: 8908423Abstract: A magnetoresistive effect element includes: a magnetization free layer having an invertible magnetization; an insulating layer being adjacent to the magnetization free layer; and a magnetization fixed layer being adjacent to the insulation layer and in an opposite side of the insulation layer to the magnetization free layer. The magnetization free layer includes: a first magnetization free layer being adjacent to the insulating layer and comprising Fe or Co; and a second magnetization free layer being adjacent to the first magnetization layer and comprising NiFeB.Type: GrantFiled: November 22, 2010Date of Patent: December 9, 2014Assignee: NEC CorporationInventor: Hiroaki Honjou
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Publication number: 20130075847Abstract: A magnetic memory has: a pinning layer being a perpendicular magnetic film whose magnetization direction is fixed; an underlayer formed on the pinning layer; and a data storage layer being a perpendicular magnetic film formed on the underlayer. The data storage layer has: a magnetization free region whose magnetization direction is reversible; and a magnetization fixed region magnetically coupled with the pinning layer through the underlayer. A magnetization direction of the magnetization fixed region is fixed by the magnetic coupling. The underlayer has a magnetic underlayer made of a magnetic material.Type: ApplicationFiled: March 16, 2011Publication date: March 28, 2013Applicant: NEC CORPORATIONInventor: Hiroaki Honjou
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Publication number: 20120281463Abstract: A magnetoresistive effect element includes: a magnetization free layer having an invertible magnetization; an insulating layer being adjacent to the magnetization free layer; and a magnetization fixed layer being adjacent to the insulation layer and in an opposite side of the insulation layer to the magnetization free layer. The magnetization free layer includes: a first magnetization free layer being adjacent to the insulating layer and comprising Fe or Co; and a second magnetization free layer being adjacent to the first magnetization layer and comprising NiFeB.Type: ApplicationFiled: November 22, 2010Publication date: November 8, 2012Applicant: NEC CORPORATIONInventor: Hiroaki Honjou
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Patent number: 8300456Abstract: An MRAM has a pinned layer and a magnetic recording layer connected to the pinned layer through a tunnel barrier layer. The magnetic recording layer has a first free layer, a second free layer being in contact with the tunnel barrier layer, and an intermediate layer provided between the first free layer and the second free layer. The first free layer includes a magnetization switching region whose magnetization direction can be switched by domain wall motion method. The second free layer has no domain wall. The intermediate layer is formed to cover at least the magnetization switching region. The magnetization switching region and the second free layer are magnetically coupled to each other through the intermediate layer.Type: GrantFiled: October 22, 2007Date of Patent: October 30, 2012Assignee: NEC CorporationInventors: Hiroaki Honjou, Tetsuhiro Suzuki, Norikazu Ohshima
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Publication number: 20100046288Abstract: An MRAM according to the present invention has a pinned layer 60 and a magnetic recording layer 40 connected to the pinned layer 60 through a tunnel barrier layer 50. The magnetic recording layer 40 has a first free layer 10, a second free layer 30 being in contact with the tunnel barrier layer 50, and an intermediate layer 20 provided between the first free layer 10 and the second free layer 30. The first free layer 10 includes a magnetization switching region 13, a first magnetization fixed region 11 and a second magnetization fixed region 12. The magnetization switching region 13 has reversible magnetization and overlaps the second free layer 30. The first magnetization fixed region 11 is connected to a first boundary B1 of the magnetization switching region 13 and its magnetization orientation is fixed in a first direction.Type: ApplicationFiled: October 22, 2007Publication date: February 25, 2010Inventors: Hiroaki Honjou, Tetsuhiro Suzuki, Norikazu Ohshima
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Patent number: 7372673Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.Type: GrantFiled: May 31, 2005Date of Patent: May 13, 2008Assignee: NEC CorporationInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
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Publication number: 20050219772Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.Type: ApplicationFiled: May 31, 2005Publication date: October 6, 2005Applicant: NEC CorporationInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
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Patent number: 6950290Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.Type: GrantFiled: September 12, 2002Date of Patent: September 27, 2005Assignee: NEC CorporationInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
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Patent number: 6798626Abstract: A magnetoresistive effect element which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the element and a magnetic recording apparatus utilizing the element. This magnetoresistive effect element utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.Type: GrantFiled: February 3, 2003Date of Patent: September 28, 2004Assignee: NEC CorporationInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Shinsaku Saitoh
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Patent number: 6624987Abstract: A magnetoresistive effect head which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the head and a magnetic recording apparatus utilizing the head. This magnetoresistive effect head utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.Type: GrantFiled: May 31, 2000Date of Patent: September 23, 2003Assignee: NEC CorporationInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Shinsaku Saitoh
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Publication number: 20030151859Abstract: A magnetoresistive effect element which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the element and a magnetic recording apparatus utilizing the element. This magnetoresistive effect element utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.Type: ApplicationFiled: February 3, 2003Publication date: August 14, 2003Applicant: NEC CORPORATIONInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Shinsaku Saitoh
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Patent number: 6542342Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.Type: GrantFiled: November 29, 1999Date of Patent: April 1, 2003Assignee: NEC CorporationInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
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Patent number: 6538861Abstract: A magnetoresistive head whose operation depends on a magnetoresistive effect is configured using a ferromagnetic tunnel junction (MTJ) film, which is arranged between a lower electrode and an upper electrode. The ferromagnetic tunnel junction film is basically configured using a set of a free layer, a barrier layer and a fixing layer, which are sequentially formed and laminated on the lower electrode. Herein, the ferromagnetic tunnel junction film is designed to avoid electrostatic destruction in manufacture by prescribed measures. For example, the barrier layer is reduced in thickness at a terminal portion as compared with a center portion. Or, the barrier layer has a defect at the terminal portion. In addition, it is possible to provide a conductor in connection with the barrier layer in proximity to its terminal portion.Type: GrantFiled: June 19, 2000Date of Patent: March 25, 2003Assignee: NEC CorporationInventors: Kazuhiko Hayashi, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Kunihiko Ishihara, Tamaki Toba, Hisanao Tsuge, Atsushi Kamijo
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Publication number: 20030035256Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.Type: ApplicationFiled: September 12, 2002Publication date: February 20, 2003Applicant: NEC CorporationInventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo