Patents by Inventor Yuzo Kamiguchi
Yuzo Kamiguchi 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: 10347313Abstract: According to one embodiment, a magnetic memory includes: magnetoresistive effect elements arranged on an conductive layer; and a first circuit which passes a write current through the conductive layer and applies a control voltage to the magnetoresistive effect elements, to write data including a first value and a second value into the magnetoresistive effect elements. The first circuit adjusts at least one of a write sequence of the first value and the second value, a current value of the write current, and a pulse width of the write current, on the basis of an arrangement of the first value and the second value in the data.Type: GrantFiled: March 8, 2018Date of Patent: July 9, 2019Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Naoharu Shimomura, Tomoaki Inokuchi, Katsuhiko Koui, Yuzo Kamiguchi, Hiroaki Yoda, Hideyuki Sugiyama
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Publication number: 20190088302Abstract: According to one embodiment, a magnetic memory includes: magnetoresistive effect elements arranged on an conductive layer; and a first circuit which passes a write current through the conductive layer and applies a control voltage to the magnetoresistive effect elements, to write data including a first value and a second value into the magnetoresistive effect elements. The first circuit adjusts at least one of a write sequence of the first value and the second value, a current value of the write current, and a pulse width of the write current, on the basis of an arrangement of the first value and the second value in the data.Type: ApplicationFiled: March 8, 2018Publication date: March 21, 2019Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Naoharu SHIMOMURA, Tomoaki INOKUCHI, Katsuhiko KOUI, Yuzo KAMIGUCHI, Hiroaki YODA, Hideyuki SUGIYAMA
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Patent number: 8085511Abstract: A magnetoresistance effect element includes a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic metal intermediate layer located between said pinned layer and said free layer. The element also includes a pair of electrodes electrically connected to the magnetoresistance effect film to supply a sense current perpendicularly to a film plane of the magnetoresistance effect film. At least one of the pinned layer and the free layer may include a thin-film insertion layer.Type: GrantFiled: September 23, 2008Date of Patent: December 27, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
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Patent number: 7897274Abstract: A magnetoresistive device includes a magnetization pinned layer, a magnetization free layer, a nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer, and electrodes allowing a sense current to flow in a direction substantially perpendicular to the plane of the stack including the magnetization pinned layer, the nonmagnetic intermediate layer and the magnetization free layer. At least one of the magnetization pinned layer and the magnetization free layer is substantially formed of a binary or ternary alloy represented by the formula FeaCobNic (where a+b+c=100 at %, and a?75 at %, b?75 at %, and c?63 at %), or formed of an alloy having a body-centered cubic crystal structure.Type: GrantFiled: March 13, 2007Date of Patent: March 1, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Masatoshi Yoshikawa, Yuzo Kamiguchi, Hitoshi Iwasaki, Masashi Sahashi
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Patent number: 7738220Abstract: A magnetoresistance effect element, comprising a nonmagnetic spacer layer, first and second ferromagnetic layers separated by the nonmagnetic spacer layer, the first ferromagnetic layer having a magnetization direction at an angle relative to a magnetization direction of the second ferromagnetic layer at zero applied magnetic field, the magnetization of the first ferromagnetic layer freely rotating in a magnetic field signal, a magnetoresistance effect-improving layer comprising a plurality of metal films and disposed in contact with the first ferromagnetic layer so that the first ferromagnetic layer is disposed between the nonmagnetic spacer layer and the magnetoresistance effect-improving layer, one of the plurality of metal films disposed in contact with the first ferromagnetic layer contains metal element of not solid solution with metal element of the first ferromagnetic layer and a nonmagnetic underlayer or a nonmagnetic protecting layer disposed in contact with the magnetoresistance effect-improving laType: GrantFiled: July 17, 2007Date of Patent: June 15, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatoshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
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Patent number: 7494724Abstract: A method of manufacturing a magnetoresistance effect element includes forming an insulating layer on a first ferromagnetic layer, forming an aperture reaching the first ferromagnetic layer by thrusting a needle from the top surface of the insulating layer, and depositing a ferromagnetic material to form a second ferromagnetic layer overlying the insulating layer which buries the aperture. The aperture can have an opening width not larger than 20 nm. A current flowing between the first ferromagnetic layer and the needle can be monitored, and thrusting of the needle an be interrupted when the current reaches a predetermined value.Type: GrantFiled: July 3, 2007Date of Patent: February 24, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Okuno, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
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Publication number: 20090034134Abstract: A magnetoresistance effect element includes a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic metal intermediate layer located between said pinned layer and said free layer. The element also includes a pair of electrodes electrically connected to the magnetoresistance effect film to supply a sense current perpendicularly to a film plane of the magnetoresistance effect film. At least one of the pinned layer and the free layer may include a thin-film insertion layer.Type: ApplicationFiled: September 23, 2008Publication date: February 5, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koul, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
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Patent number: 7443004Abstract: In a spin valve type element, an interface insertion layer (32, 34) of a material exhibiting large spin-dependent interface scattering is inserted in a location of a magnetically pinned layer (16) or a magnetically free layer (20) closer to a nonmagnetic intermediate layer (18). A nonmagnetic back layer (36) may be additionally inserted as an interface not in contact with the nonmagnetic intermediate layer to increase the output by making use of spin-dependent interface scattering along the interface between the pinned layer and the nonmagnetic back layer or between the free layer and the nonmagnetic back layer.Type: GrantFiled: November 22, 2005Date of Patent: October 28, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
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Patent number: 7440239Abstract: It is possible to obtain sensitivity which can achieve an excellent error rate with a high recording density. There are provided a magnetization free layer which has two opposed main surfaces, one of which is set to be generally parallel to an air bearing surface; an intermediate layer which is formed on an opposite side face of the magnetization free layer from a medium to come in contact with the magnetization free layer; and a pair of magnetization pinned layers which are formed on an opposite side face of the intermediate layer from the magnetization free layer to come in contact with the intermediate layer and extend outwardly. A sense current flows from one magnetization pinned layer to the other magnetization pinned layer through the magnetization free layer.Type: GrantFiled: September 29, 2003Date of Patent: October 21, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Yuzo Kamiguchi, Masayuki Takagishi, Yuichi Ohsawa
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Patent number: 7375405Abstract: A magnetoresistance effect (MR) device incorporating a spin valve film, and a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device, wherein the magnetization direction of a free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. A pinned magnetic layer includes a pair of ferromagnetic films antiferromagnetically coupled to each other via a coupling film existing therebetween. The magnetization direction of either one of the pair of ferromagnetic films constituting the pinned magnetic layer is maintained, and a nonmagnetic high-conductivity layer is disposed adjacent to a first ferromagnetic layer on the side opposite to the side on which the first ferromagnetic layer is contacted with a nonmagnetic spacer layer. With that constitution, the device has extremely high sensitivity, and the bias point in the device is well controlled.Type: GrantFiled: March 15, 2005Date of Patent: May 20, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatoshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
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Patent number: 7355883Abstract: A magnetoresistance effect element includes a first ferromagnetic layer (1), insulating layer (3) overlying the first ferromagnetic layer, and second ferromagnetic layer (2) overlying the insulating layer. The insulating layer has formed a through hole (A) having an opening width not larger than 20 nm, and the first and second ferromagnetic layers are connected to each other via the through hole.Type: GrantFiled: December 8, 2004Date of Patent: April 8, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Okuno, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
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Patent number: 7336454Abstract: A base film of a hard magnetic film containing Co as a structural element has a crystal metal base film such as a Cr film formed on the main surface of a substrate and a reactive base film (mixing layer) formed between the substrate and the crystal metal base film and having a reactive amorphous layer containing a structural element of the substrate and a structural element of the crystal metal base film. A hard magnetic film containing Co as a structural element is formed on the crystal metal base film. With the crystal metal base film such as the Cr film formed on an amorphous layer, a hard magnetic film with a bi-crystal structure can be obtained with high reproducibility. With the hard magnetic film, magnetic characteristics such as coercive force Hc, residual magnetization Mr, saturated magnetization Ms, and square ratio S can be improved without need to use a thick base film.Type: GrantFiled: May 4, 2006Date of Patent: February 26, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Shin-ichi Nakamura, Yuzo Kamiguchi, Hitoshi Iwasaki, Akio Hori, Susumu Hashimoto
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Publication number: 20080013222Abstract: A method of manufacturing a magnetoresistance effect element includes forming an insulating layer on a first ferromagnetic layer, forming an aperture reaching the first ferromagnetic layer by thrusting a needle from the top surface of the insulating layer, and depositing a ferromagnetic material to form a second ferromagnetic layer overlying the insulating layer which buries the aperture. The aperture can have an opening width not larger than 20 nm. A current flowing between the first ferromagnetic layer and the needle can be monitored, and thrusting of the needle an be interrupted when the current reaches a predetermined value.Type: ApplicationFiled: July 3, 2007Publication date: January 17, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Shiho OKUNO, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
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Patent number: 7295407Abstract: A magnetoresistance effect element a stacked film including a magnetization fixed layer in which the direction of magnetization is substantially fixed to one direction, and a magnetization free layer in which the direction of magnetization varies in response to an external magnetic field, an electrode connected to a part of a principal plane of the stacked film, the magnetoresistance effect element having a resistance varying in response to a relative angle between the direction of magnetization in the magnetization fixed layer and the direction of magnetization in the magnetization free layer, a sense current detecting the variation of the resistance being applied to the film planes of the magnetization fixed layer and the magnetization free layer via the electrode in a direction substantially perpendicular to the magnetization fixed layer and the magnetization free layer.Type: GrantFiled: June 8, 2007Date of Patent: November 13, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Hiroaki Yoda, Yuzo Kamiguchi, Tomohiko Nagata
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Publication number: 20070230065Abstract: A magnetoresistance effect element a stacked film including a magnetization fixed layer in which the direction of magnetization is substantially fixed to one direction, and a magnetization free layer in which the direction of magnetization varies in response to an external magnetic field, an electrode connected to a part of a principal plane of the stacked film, the magnetoresistance effect element having a resistance varying in response to a relative angle between the direction of magnetization in the magnetization fixed layer and the direction of magnetization in the magnetization free layer, a sense current detecting the variation of the resistance being applied to the film planes of the magnetization fixed layer and the magnetization free layer via the electrode in a direction substantially perpendicular to the magnetization fixed layer and the magnetization free layer.Type: ApplicationFiled: June 8, 2007Publication date: October 4, 2007Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hiromi YUASA, Hiroaki Yoda, Yuzo Kamiguchi, Tomohiko Nagata
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Patent number: 7265950Abstract: A magnetoresistance effect element includes a first ferromagnetic layer (1), insulating layer (3) overlying the first ferromagnetic layer, and second ferromagnetic layer (2) overlying the insulating layer. The insulating layer has formed a through hole (A) having an opening width not larger than 20 nm, and the first and second ferromagnetic layers are connected to each other via the through hole.Type: GrantFiled: September 8, 2004Date of Patent: September 4, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Okuno, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
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Patent number: 7248448Abstract: Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween.Type: GrantFiled: September 10, 2004Date of Patent: July 24, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatoshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
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Patent number: 7245461Abstract: There is provided a magnetoresistance effect element capable of precisely defining the active region in a CPP type MR element and of effectively suppressing and eliminating the influence of a magnetic field due to current from an electrode, and a magnetic head and magnetic reproducing system using the same. The active region of the MR element is defined by the area of a portion through which a sense current flows. Moreover, the shape of the cross section of a pillar electrode or pillar non-magnetic material for defining the active region of the element is designed to extend along the flow of a magnetic flux so as to efficiently read only a signal from a track directly below the active region. When the magnetic field due to current from the pillar electrode can not be ignored, the magnetic flux from a recording medium asymmetrically enters yokes and the magnetization free layer of the MR element to some extent.Type: GrantFiled: February 6, 2006Date of Patent: July 17, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Hiroaki Yoda, Yuzo Kamiguchi, Tomohiko Nagata
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Patent number: 7240419Abstract: A method of manufacturing a magnetoresistance effect element includes forming an insulating layer on a first ferromagnetic layer, forming an aperture reaching the first ferromagnetic layer by thrusting a needle from the top surface of the insulating layer, and depositing a ferromagnetic material to form a second ferromagnetic layer overlying the insulating layer which buries the aperture. The aperture can have an opening width not larger than 20 nm. A current flowing between the first ferromagnetic layer and the needle can be monitored, and thrusting of the needle can be interrupted when the current reaches a predetermined value.Type: GrantFiled: March 10, 2004Date of Patent: July 10, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Okuno, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
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Publication number: 20070154740Abstract: A magnetoresistive device includes a magnetization pinned layer, a magnetization free layer, a nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer, and electrodes allowing a sense current to flow in a direction substantially perpendicular to the plane of the stack including the magnetization pinned layer, the nonmagnetic intermediate layer and the magnetization free layer. At least one of the magnetization pinned layer and the magnetization free layer is substantially formed of a binary or ternary alloy represented by the formula FeaCobNic (where a+b+c=100 at %, and a?75 at %, b?75 at %, and c?63 at %), or formed of an alloy having a body-centered cubic crystal structure.Type: ApplicationFiled: March 13, 2007Publication date: July 5, 2007Inventors: Hiromi Yuasa, Masatoshi Yoshikawa, Yuzo Kamiguchi, Hitoshi Iwasaki, Masashi Sahashi