Patents by Inventor Tetsuhiro Suzuki
Tetsuhiro Suzuki 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: 8729648Abstract: A magnetic body device has a stacked structure comprising an underlying layer, a magnetic body layer, and a cap layer. The material for the underlying layer is different from that for the cap layer. The magnetic body layer has a free magnetization region having perpendicular magnetic anisotropy and a first characteristic change region and a second characteristic change region situated on both sides of the free magnetization region in a first in-plane direction. The perpendicular magnetic anisotropy of the first characteristic change region and the second characteristic change region is at a level lower than that of the free magnetization region. An external magnetic field containing a component in the first in-plane direction is applied to the free magnetization region. Further, a current in the first in-plane direction is supplied to the free magnetization region.Type: GrantFiled: April 16, 2013Date of Patent: May 20, 2014Assignee: Renesas Electronics CorporationInventors: Tetsuhiro Suzuki, Katsumi Suemitsu, Eiji Kariyada
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Patent number: 8687414Abstract: A magnetic memory cell includes: a magnetization recording layer; and a magnetic tunneling junction section. The magnetization recording layer includes a ferromagnetic layer with perpendicular magnetic anisotropy. The magnetic tunneling junction section is used for reading information in the magnetization recording layer. The magnetization recording layer includes two domain wall moving areas.Type: GrantFiled: December 24, 2009Date of Patent: April 1, 2014Assignee: NEC CorporationInventors: Kiyokazu Nagahara, Shunsuke Fukami, Nobuyuki Ishiwata, Tetsuhiro Suzuki, Norikazu Ohshima
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Publication number: 20140010004Abstract: A magnetic memory includes: a base layer; a magnetization free layer; a barrier layer; and a magnetization reference layer. The magnetization free layer, with which the base layer is covered, has invertible magnetization and is magnetized approximately uniformly. The barrier layer, with which the magnetization free layer is covered, is composed of material different from material of the base layer. The magnetization reference layer is arranged on the barrier layer and has a fixed magnetization. When the magnetization of the magnetization free layer is inverted, a first writing current is made to flow from one end to the other end of the magnetization free layer in an in-plane direction without through the magnetization reference layer.Type: ApplicationFiled: October 14, 2011Publication date: January 9, 2014Applicant: RENESAS ELECTRONICS CORPORATIONInventor: Tetsuhiro Suzuki
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Patent number: 8625327Abstract: A domain wall motion type MRAM has: a magnetic recording layer 10 being a ferromagnetic layer having perpendicular magnetic anisotropy; a pair of current supply terminals 14a and 14b connected to the magnetic recording layer 10 for supplying a current to the magnetic recording layer 10; and an anti-ferromagnetic layer 45 being in contact with a first region R1 of the magnetic recording layer 10. The first region R1 includes a part of a current supply region RA of the magnetic recording layer 10 that is between the pair of current supply terminals 14a and 14b.Type: GrantFiled: July 2, 2009Date of Patent: January 7, 2014Assignee: NEC CorporationInventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Norikazu Oshima, Nobuyuki Ishiwata
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Patent number: 8592930Abstract: A magnetic memory element includes: a first magnetization free layer; a non-magnetic layer; a reference layer; a first magnetization fixed layer group; and a first blocking layer. The first magnetization free layer is composed of ferromagnetic material with perpendicular magnetic anisotropy and includes a first magnetization fixed region, a second magnetization fixed region and a magnetization free region. The non-magnetic layer is provided near the first magnetization free layer. The reference layer is composed of ferromagnetic material and provided on the non-magnetic layer. The first magnetization fixed layer group is provided near the first magnetization fixed region. The first blocking layer is provided being sandwiched between the first magnetization fixed layer group and the first magnetization fixed region or in the first magnetization fixed layer group.Type: GrantFiled: October 21, 2010Date of Patent: November 26, 2013Assignee: NEC CorporationInventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
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Publication number: 20130285176Abstract: A magnetic body device has a stacked structure comprising an underlying layer, a magnetic body layer, and a cap layer. The material for the underlying layer is different from that for the cap layer. The magnetic body layer has a free magnetization region having perpendicular magnetic anisotropy and a first characteristic change region and a second characteristic change region situated on both sides of the free magnetization region in a first in-plane direction. The perpendicular magnetic anisotropy of the first characteristic change region and the second characteristic change region is at a level lower than that of the free magnetization region. An external magnetic field containing a component in the first in-plane direction is applied to the free magnetization region. Further, a current in the first in-plane direction is supplied to the free magnetization region.Type: ApplicationFiled: April 16, 2013Publication date: October 31, 2013Applicant: Renesas Electronics CorporationInventors: Tetsuhiro SUZUKI, Katsumi SUEMITSU, Eiji KARIYADA
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Patent number: 8565011Abstract: An initialization method is provided for a magnetic memory element including: a data recording layer having perpendicular magnetic anisotropy which includes: a first magnetization fixed region, a second magnetization fixed region, and a magnetization free region coupled to the first magnetization fixed region and the second magnetization fixed region, the data recording layer being structure so that the coercive force of the first magnetization fixed region being different from that of the second magnetization fixed region. The initialization method includes steps of: directing the magnetizations of the first magnetization fixed region, the second magnetization fixed region and the magnetization free region in the same direction; and applying a magnetic field having both components perpendicular to and parallel to the magnetic anisotropy of the data recording layer to the data recording layer.Type: GrantFiled: October 29, 2009Date of Patent: October 22, 2013Assignee: NEC CorporationInventors: Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki, Nobuyuki Ishiwata, Norikazu Ohshima
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Patent number: 8559214Abstract: A magnetic memory cell is provided with a magnetization record layer and a magnetic tunnel junction section. The magnetization record layer is a ferromagnetic layer having a perpendicular magnetic anisotropy. The magnetic tunnel junction section is used to read data from the magnetization record layer. The magnetization record layer has a plurality of domain wall motion regions.Type: GrantFiled: December 24, 2009Date of Patent: October 15, 2013Assignee: NEC CorporationInventors: Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki, Nobuyuki Ishiwata, Norikazu Ohshima
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Patent number: 8537604Abstract: A magnetoresistance element is provided with: a magnetization recording layer that is a ferromagnetic layer. The magnetization recording layer includes: a magnetization reversal region having a reversible magnetization; a first magnetization fixed region connected to a first boundary of the magnetization reversal region and having a magnetization direction fixed in a first direction; and a second magnetization fixed region connected to a second boundary of the magnetization reversal region and having a magnetization direction fixed in a second direction. At least one magnetization reversal facilitation structure which is a structure in which a magnetization is reversed more easily than the remaining portion is provided for a portion of the second magnetization fixed region.Type: GrantFiled: October 16, 2009Date of Patent: September 17, 2013Assignee: NEC CorporationInventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
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Patent number: 8514616Abstract: A magnetoresistive effect element includes: a magnetization free layer; a non-magnetic insertion layer provided adjacent to the magnetization free layer; a magnetic insertion layer provided adjacent to the non-magnetic insertion layer and opposite to the magnetization free layer with respect to the non-magnetic insertion layer; a spacer layer provided adjacent to the magnetic insertion layer and opposite to the non-magnetic insertion layer with respect to the magnetic insertion layer; and a first magnetization fixed layer provided adjacent to the spacer layer and opposite to the magnetic insertion layer with respect to the spacer layer. The magnetization free layer and the first magnetization fixed layer have magnetization components in directions approximately perpendicular to a film surface. The magnetization free layer includes two magnetization fixed portions and a domain wall motion portion arranged between the two magnetization fixed portions.Type: GrantFiled: February 15, 2010Date of Patent: August 20, 2013Assignee: NEC CorporationInventors: Nobuyuki Ishiwata, Norikazu Ohshima, Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki
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Patent number: 8503222Abstract: A non-volatile logic circuit includes an input section, a control section and an output section. The input section has perpendicular magnetic anisotropy and has a ferromagnetic layer whose magnetization state is changeable. The control section includes a ferromagnetic layer. The output section is provided in a neighborhood of the input section and the control section and includes a magnetic tunnel junction element whose magnetization state is changeable. The magnetization state of the input section is changed based on the magnetization state. A magnetization state of the magnetic tunnel junction element of the output section which state is changed based on the magnetization state of the ferromagnetic material of the control section and the magnetization state of the ferromagnetic material of the input section.Type: GrantFiled: January 21, 2010Date of Patent: August 6, 2013Assignee: NEC CorporationInventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Nobuyuki Ishiwata, Tadahiko Sugibayashi, Noboru Sakimura, Ryusuke Nebashi
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Publication number: 20130175645Abstract: A magnetoresistive effect element of the present invention includes: a domain wall motion layer, a spacer layer and a reference layer. The domain wall motion layer is made of ferromagnetic material with perpendicular magnetic anisotropy. The spacer layer is formed on the domain wall motion layer and made of non-magnetic material. The reference layer is formed on the spacer layer and made of ferromagnetic material, magnetization of the reference layer being fixed. The domain wall motion layer includes at least one domain wall, and stores data corresponding to a position of the domain wall. An anisotropy magnetic field of the domain wall motion layer is larger than a value in which the domain wall motion layer can hold the perpendicular magnetic anisotropy, and smaller than an essential value of an anisotropy magnetic field of the ferromagnetic material of the domain wall motion layer.Type: ApplicationFiled: December 14, 2010Publication date: July 11, 2013Applicant: NEC CORPORATIONInventors: Tadahiko Sugibayashi, Eiji Kariyada, Kaoru Mori, Norikazu Ohshima, Shunsuke Fukami, Tetsuhiro Suzuki, Hironobu Tanigawa, Sadahiko Miura, Nobuyuki Ishiwata
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Publication number: 20130140660Abstract: In a perpendicular magnetization domain wall motion MRAM in which the magnetizations of both ends of a magnetization free layer are pinned by magnetization pinned layers, the increase of a write current due to leakage magnetic field from the magnetization pinned layer is prevented. A first displacement is present between a first boundary line and a first vertical line, where a curve portion, which crosses a first magnetization free layer, of an outer circumferential line of a first magnetization pinned layer is the first boundary line, a segment which links a center of a magnetization free region and a center of a first magnetization pinned region is a first segment, and a segment, which is a vertical line of the first segment, and which comes in contact with the first boundary line is the first vertical line.Type: ApplicationFiled: June 16, 2011Publication date: June 6, 2013Inventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Nobuyuki Ishiwata, Norikazu Ohshima
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Publication number: 20130113058Abstract: A magnetic memory element includes: a first magnetization free layer configured to be composed of ferromagnetic material with perpendicular magnetic anisotropy; a reference layer configured to be provided near the first magnetization free layer; a non-magnetic layer configured to be provided adjacent to the reference layer; and a step formation layer configured to be provided under the first magnetization free layer. The first magnetization free layer includes: a first magnetization fixed region of which magnetization is fixed, a second magnetization fixed region of which magnetization is fixed, and a magnetization free region configured to be connected with the first magnetization fixed region and the second magnetization fixed region. The first magnetization free layer has at least one of a step, a groove and a protrusion inside.Type: ApplicationFiled: March 9, 2011Publication date: May 9, 2013Applicant: NEC CORPORATIONInventors: Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki
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Patent number: 8379429Abstract: A domain wall motion element has a magnetic recording layer 10 that is formed of a ferromagnetic film and has a domain wall DW. The magnetic recording layer 10 has: a pair of end regions 11-1 and 11-2 whose magnetization directions are fixed; and a center region 12 sandwiched between the pair of end regions 11-1 and 11-2, in which the domain wall. DW moves. A first trapping site TS1 by which the domain wall DW is trapped is formed at a boundary between the end region 11-1, 11-2 and the center region 12. Furthermore, at least one second trapping site TS2 by which the domain wall DW is trapped is formed within the center region 12.Type: GrantFiled: January 13, 2009Date of Patent: February 19, 2013Assignee: NEC CorporationInventors: Nobuyuki Ishiwata, Tetsuhiro Suzuki, Norikazu Ohshima, Kiyokazu Nagahara, Shunsuke Fukami
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Patent number: 8363461Abstract: A magnetic memory includes a magnetization recording layer, a first terminal, a second terminal, a magnetization pinned layer and a non-magnetic layer. The magnetization recording layer has a vertical magnetic anisotropy and includes a ferromagnetic layer. The first terminal is connected to one end of a first region in the magnetization recording layer. The second terminal is connected to the other end of the first region. The non-magnetic layer is arranged on the first region. The magnetization pinned layer is arranged on the non-magnetic layer and is located on the side opposite to the first region. The magnetization recording layer includes: a first extension portion located outside the first terminal in the magnetization recording layer; and a property changing structure that is arranged in the first extension portion and substantially changes a magnetization switching property of the magnetization recording layer.Type: GrantFiled: June 26, 2009Date of Patent: January 29, 2013Assignee: NEC CorporationInventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
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Publication number: 20120278582Abstract: A magnetic memory element includes: a first magnetization free layer; a non-magnetic layer; a reference layer; a first magnetization fixed layer group; and a first blocking layer. The first magnetization free layer is composed of ferromagnetic material with perpendicular magnetic anisotropy and includes a first magnetization fixed region, a second magnetization fixed region and a magnetization free region. The non-magnetic layer is provided near the first magnetization free layer. The reference layer is composed of ferromagnetic material and provided on the non-magnetic layer. The first magnetization fixed layer group is provided near the first magnetization fixed region. The first blocking layer is provided being sandwiched between the first magnetization fixed layer group and the first magnetization fixed region or in the first magnetization fixed layer group.Type: ApplicationFiled: October 21, 2010Publication date: November 1, 2012Applicant: NEC CORPORATIONInventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
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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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Patent number: 8238135Abstract: A magnetic recording layer 10 of an MRAM has a first magnetization fixed region 11, a second magnetization fixed region 12 and a magnetization switching region 13. The magnetization switching region 13 has reversible magnetization and overlaps with a pinned layer. The first magnetization fixed region 11 is connected to a first boundary B1 of the magnetization switching region 13 and its magnetization direction is fixed to a first direction. The second magnetization fixed region 12 is connected to a second boundary B2 of the magnetization switching region 13 and its magnetization direction is fixed to a second direction. Both of the first direction and the second direction are toward the magnetization switching region 13 or away from the magnetization switching region 13. The damping coefficient ? in at least a portion R1, R2 of the magnetization fixed regions 11 and 12 is larger than the damping coefficient ? in the magnetization switching region 13.Type: GrantFiled: January 15, 2008Date of Patent: August 7, 2012Assignee: NEC CorporationInventors: Tetsuhiro Suzuki, Norikazu Ohshima, Hideaki Numata
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Patent number: 8194436Abstract: A magnetic random access memory includes: a first ferromagnetic layer; an insulating layer provided adjacent to the first ferromagnetic layer; and a first magnetization pinned layer provided adjacent to the insulating layer on a side opposite to the first ferromagnetic layer. The first ferromagnetic layer includes a magnetization free region, a first magnetization pinned region, and a second magnetization pinned region. The magnetization free region has reversible magnetization, and overlaps with the second ferromagnetic layer. The first magnetization pinned region has first pinned magnetization, and is connected to a part of the magnetization free region. The second magnetization pinned region has second pinned magnetization, and is connected to a part of the magnetization free region. The first ferromagnetic layer has magnetic anisotropy in a direction perpendicular to a film surface.Type: GrantFiled: July 7, 2008Date of Patent: June 5, 2012Assignee: NEC CorporationInventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata