Patents by Inventor Shiho Nakamura
Shiho Nakamura 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: 7532503Abstract: A magnetic recording element includes a first fixed layer having a first and second face and having a magnetization direction fixed in a direction penetrating the first and second face. A free layer has a third and fourth face, a magnetization easy and hard axis both extending along the third or fourth face, and a magnetization direction which changes according to a direction of a current flowing through the first and fourth face with a magnetic field applied in a fixed direction or according to a direction of a magnetic field applied to the free layer with a current flowing through the first and fourth face in a fixed direction. A nonmagnetic first intermediate layer is provided between the second and third face. A magnetic field generating layer applies a magnetic field smaller than the anisotropy field of the free layer to the free layer along the magnetization hard axis.Type: GrantFiled: December 19, 2005Date of Patent: May 12, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Hirofumi Morise, Shiho Nakamura, Shigeru Haneda, Takahiro Hirai
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Publication number: 20090098412Abstract: A magnetic recording element includes a multilayer having a surface and a pair of electrodes. The multilayer has a first magnetic fixed layer whose magnetization is substantially fixed in a first direction substantially perpendicular to the surface. The multilayer also has a second magnetic fixed layer whose magnetization is substantially fixed in a second direction opposite to the first direction substantially perpendicular to the surface. A third magnetic layer is provided between the first and second magnetic layers. The direction of magnetization of the third ferromagnetic layer is variable. A first intermediate layer is provided between the first and the third magnetic layers. A second intermediate layer is provided between the second and the third magnetic layers. The pair of electrodes is capable of supplying an electric current flowing in a direction substantially perpendicular to the surface to the multilayer.Type: ApplicationFiled: October 3, 2008Publication date: April 16, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yuichi Ohsawa, Shiho Nakamura, Hirofumi Morise, Satoshi Yanagi, Daisuke Saida
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Publication number: 20090052237Abstract: A magnetic memory element includes a laminated construction of a first electrode, a first pinned layer, a first intermediate layer, a memory layer, a second intermediate layer, a second pinned layer and a second electrode, and a third electrode coupled to the first intermediate layer and not directly coupled to the memory layer. The magnetization directions of the first pinned layer, the second pinned layer, and the memory layer are parallel or antiparallel to each other. The magnetization direction of the memory layer takes a first direction when the current is passed with a first polarity so that the current flowing through the first pinned layer exceeds a first threshold. The magnetization direction of the memory layer takes a second direction when the current is passed with a second polarity so that the current flowing through the first pinned layer exceeds a second threshold.Type: ApplicationFiled: April 22, 2008Publication date: February 26, 2009Inventors: Hirofumi Morise, Shiho Nakamura, Satoshi Yanagi, Yuichi Ohsawa, Daisuke Saida
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Patent number: 7486486Abstract: A magnetic device includes a first ferromagnetic layer in which magnetic layers and one or more nonmagnetic layers are alternately stacked, a second ferromagnetic layer having magnetization substantially fixed to a second direction, a third ferromagnetic layer provided between the first and second ferromagnetic layers and having a variable direction of magnetization, and a couple of electrodes configured to provide write current between the first and second ferromagnetic layers so that the direction of magnetization of the third ferromagnetic layer is determined depending on a direction of the current. At least one layer of the magnetic layers has magnetization substantially fixed to a first direction. Two or more layers of the magnetic layers are ferromagnetically coupled via the nonmagnetic layers. The ferromagnetic coupling has a strength such that a parallel magnetic alignment of the magnetic layers is maintained when the write current is passed.Type: GrantFiled: September 30, 2004Date of Patent: February 3, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Shigeru Haneda
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Publication number: 20090015958Abstract: A magnetic recording device includes: a laminated body including: a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer; and a third ferromagnetic layer with a variable magnetization direction. The magnetization direction of the second ferromagnetic layer is determinable in response to the orientation of a current, by allowing electrons spin-polarized by passing a current in a direction generally perpendicular to the film plane of the layers of the laminated body to act on the second ferromagnetic layer, and by allowing a magnetic field generated by precession of the magnetization of the third ferromagnetic layer to act on the second ferromagnetic layer.Type: ApplicationFiled: July 11, 2008Publication date: January 15, 2009Applicant: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Hirofumi Morise, Satoshi Yanagi, Daisuke Saida, Akira Kikitsu
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Publication number: 20080298117Abstract: A semiconductor integrated circuit device, has a first variable resistor element and a second variable resistor element whose resistances are changed complementarily depending on a current; and a current path switching circuit that supplies said current from a power supply by switching between current paths according to whether a normal operation mode or a read mode is input externally, wherein said power supply is turned off and then turned on again in said normal operation mode, and in this state, data corresponding to the relationship between the magnitudes of the resistances of said first variable resistor element and said second variable resistor element is read in said read mode.Type: ApplicationFiled: October 15, 2007Publication date: December 4, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Mototsugu Hamada, Takahiro Hirai, Shiho Nakamura, Hirofumi Morise, Keiko Abe
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Patent number: 7432574Abstract: A magnetic recording element according to an example of the present invention includes a magnetic free layer whose magnetization is variable in accordance with a current direction passing through a film and whose direction of easy axis of magnetization is a direction perpendicular to a film plane, a magnetic pinned layer whose magnetization is fixed to a direction perpendicular to the film plane, and a non-magnetic barrier layer between the magnetic free layer and the magnetic pinned layer. In the magnetic free layer, a relation between a saturated magnetization Ms (emu/cc) and an anisotropy field Han (Oe) satisfies Han>12.57 Ms, and Han<1.2 E7 Ms?1+12.57 Ms.Type: GrantFiled: March 20, 2007Date of Patent: October 7, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Hirofumi Morise
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Publication number: 20080213627Abstract: A magnetoresistance effect device includes: an insulator layer; a first and second ferromagnetic layer laminated to sandwich the insulator layer; a magnetic bias layer laminated with the second ferromagnetic layer; and a connecting section formed discontinuously on a side face of the insulator layer. The connecting section is not interposed between the second ferromagnetic layer and the magnetic bias layer. The connecting section is made of a ferromagnetic material, and electrically connecting between the first ferromagnetic layer and the second ferromagnetic layer. A method for manufacturing a magnetoresistance effect device includes: laminating a first and second ferromagnetic layer to sandwich an insulator layer, and laminating a magnetic bias layer with the second ferromagnetic layer; and forming a connecting section for electrically connecting between the first ferromagnetic layer and the second ferromagnetic layer by discontinuously forming a ferromagnetic material on a side face of the insulator layer.Type: ApplicationFiled: February 29, 2008Publication date: September 4, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yuichi Ohsawa, Shiho Nakamura
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Publication number: 20080197431Abstract: A magnetic memory element includes a laminated construction of an electrode, a first pinned layer, a first intermediate layer, a first memory layer, a second intermediate layer, a second memory layer, a third intermediate layer, a second pinned layer and electrode. The magnetization direction of the first memory layer takes a first and a second directions and that of the second memory layer takes a third and a fourth directions corresponding to a value and polarity of a current between the electrodes. In response to the current, the second intermediate layer has an electric resistance higher than the first intermediate layer and than the third intermediate layer.Type: ApplicationFiled: September 21, 2007Publication date: August 21, 2008Applicant: Kabushiki Kaisha ToshibaInventors: Hirofumi Morise, Shiho Nakamura, Satoshi Yanagi
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Patent number: 7381480Abstract: A magnetic recording element includes a fixed layer having first and second surfacesm, a recording layer having third and fourth surfaces and being essentially made of a ferromagnetic material having first and second atomic potentials for the majority-spin band electrons and the minority-spin band electrons, a spacer layer being arranged between the fixed and recording layers and being in contact with the second and third surfaces, a cap layer having fifth and sixth surfaces, being essentially made of a nonmagnetic material having a third atomic potential less than an intermediate value between the first and second atomic potentials, and having a thickness of not more than 3 nm, the fifth surface being in contact with the fourth surface, and a reflecting layer being in contact with the sixth surface and being essentially made of a nonmagnetic material having a forth atomic potential different from the third atomic potential.Type: GrantFiled: April 29, 2005Date of Patent: June 3, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Shigeru Haneda, Hirofumi Morise
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Patent number: 7372727Abstract: A magnetic cell includes: a first ferromagnetic layer whose magnetization is substantially fixed in a first direction; a second ferromagnetic layer whose magnetization is substantially fixed in a second direction opposite to the first direction; a third ferromagnetic layer provided between the first and the second ferromagnetic layers, a direction of magnetization of the third ferromagnetic layer being variable; a first intermediate layer provided between the first and the third ferromagnetic layers; and a second intermediate layer provided between the second and the third ferromagnetic layers. The direction of magnetization of the third ferromagnetic layer can be determined under an influence of spin-polarized electrons upon the third ferromagnetic layer by passing a current between the first and the second ferromagnetic layers.Type: GrantFiled: January 10, 2006Date of Patent: May 13, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Shigeru Haneda, Yuichi Ohsawa
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Publication number: 20080080231Abstract: A nonvolatile latch circuit includes: a first gate part controlling to load or intercept an input signal based on a gate signal; a first logic gate functioning as an inverter or a gate outputting a constant voltage in response to the first control signal; a second logic gate functioning as an inverter or a gate outputting the constant voltage in response to the first control signal; a second gate part controlling to load or intercept the output of the second logic gate based on an inverted signal of the gate signal and sends the output of the second logic gate to an first input terminal of the first logic gate; and first and second injection type MTJ elements provided between the driving power supply and the first and second logic gates and changing in resistance depending upon a current flow direction.Type: ApplicationFiled: August 31, 2007Publication date: April 3, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Keiko Abe, Takahiro Hirai, Shiho Nakamura, Hirofumi Morise, Mototsugu Hamada
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Publication number: 20070228501Abstract: A magnetic recording element according to an example of the present invention includes a magnetic free layer whose magnetization is variable in accordance with a current direction passing through a film and whose direction of easy axis of magnetization is a direction perpendicular to a film plane, a magnetic pinned layer whose magnetization is fixed to a direction perpendicular to the film plane, and a non-magnetic barrier layer between the magnetic free layer and the magnetic pinned layer. In the magnetic free layer, a relation between a saturated magnetization Ms (emu/cc) and an anisotropy field Han (Oe) satisfies Han>12.57 Ms, and Han<1.2 E7 Ms?1+12.57 Ms.Type: ApplicationFiled: March 20, 2007Publication date: October 4, 2007Inventors: Shiho Nakamura, Hirofumi Morise
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Publication number: 20070211525Abstract: A magnetic switching element according to an example of the present invention includes a magnetic element, first and second electrodes which put the magnetic element therebetween, a current control section which is connected to the first and second electrodes, the current control section controlling a magnetization direction of a magnetization free section in such a manner that a current is made to flow between the magnetization free section and the magnetization fixed section, a movable conductive tube having a fixed end and a free end, and a third electrode connected to the fixed end of the conductive tube. A switching operation is performed in such a manner that a spatial position of the conductive tube is caused to change depending on the magnetization direction of the magnetization free section.Type: ApplicationFiled: March 30, 2007Publication date: September 13, 2007Applicant: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Yuichi Motoi, Shigeru Haneda, Hirofumi Morise, Takahiro Hirai
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Patent number: 7269059Abstract: A magnetic recording element, in which a spin-polarized electron is injected, has a layer whose magnetization direction is changed by the spin-polarized electron in accordance with a flow direction of the spin-polarized electron and records data in accordance with the magnetization direction. The magnetic recording element includes a free layer whose magnetization direction is changed by an action of a spin-polarized electron and has a spin polarization Pf. A pinned layer whose magnetization direction is fixed has a spin polarization Pp larger than the spin polarization Pf. An intermediate layer is interposed between the pinned layer and the free layer and consisting essentially of a nonmagnetic material.Type: GrantFiled: June 8, 2005Date of Patent: September 11, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Hirofumi Morise, Shiho Nakamura, Shigeru Haneda
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Publication number: 20070195469Abstract: A magnetoresistive effect element includes: a magnetoresistive effect film including a magnetization free layer, a magnetization fixed layer, and an intermediate layer placed between them; a magnetic coupling layer; a ferromagnetic layer; an antiferromagnetic layer; a bias mechanism portion applying a bias magnetic field to the magnetization free layer in a direction nearly parallel to a film surface of the magentoresistive effect film and nearly perpendicular to a magnetization direction of the magnetization fixed layer; and a pair of electrodes to pass a current in a direction going from the magnetization fixed layer to the magnetization free layer, and its bias point is more than 50%.Type: ApplicationFiled: November 13, 2006Publication date: August 23, 2007Applicant: Kabushiki Kaisha ToshibaInventors: Masahiro Takashita, Masayuki Takagishi, Hitoshi Iwasaki, Shiho Nakamura
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Publication number: 20070064342Abstract: A magnetic element includes a channel layer, a first magnetic electrode which is in contact with the channel layer, a second magnetic electrode which is in contact with the channel layer and is insulated from the first magnetic electrode, a first intermediate layer which is provided adjacent to the first magnetic electrode and has a first insulating layer, a first magnetic layer which is provided in contact with a surface of the first intermediate layer on an opposite side to a surface contacting the first magnetic electrode to transfer magnetization to the first magnetic electrode, a first electrode which is connected to the first magnetic electrode, and a second electrode which is connected to the second magnetic electrode, at least one of the first electrode and the second electrode outputting a first signal which changes depending on a magnetic arrangement of the first magnetic electrode and the second magnetic electrode.Type: ApplicationFiled: March 28, 2006Publication date: March 22, 2007Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Shiho Nakamura, Hirofumi Morise, Shigeru Haneda
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Publication number: 20070057278Abstract: A magnetic switching element according to an example of the present invention includes a magnetic element, first and second electrodes which put the magnetic element therebetween, a current control section which is connected to the first and second electrodes, the current control section controlling a magnetization direction of a magnetization free section in such a manner that a current is made to flow between the magnetization free section and the magnetization fixed section, a movable conductive tube having a fixed end and a free end, and a third electrode connected to the fixed end of the conductive tube. A switching operation is performed in such a manner that a spatial position of the conductive tube is caused to change depending on the magnetization direction of the magnetization free section.Type: ApplicationFiled: September 8, 2006Publication date: March 15, 2007Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Shiho Nakamura, Yuichi Motoi, Shigeru Haneda, Hirofumi Morise, Takahiro Hirai
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Patent number: 7126849Abstract: A magnetic cell includes: a first ferromagnetic layer whose magnetization is substantially fixed in a first direction; a second ferromagnetic layer whose magnetization is substantially fixed in a second direction opposite to the first direction; a third ferromagnetic layer provided between the first and the second ferromagnetic layers, a direction of magnetization of the third ferromagnetic layer being variable; a first intermediate layer provided between the first and the third ferromagnetic layers; and a second intermediate layer provided between the second and the third ferromagnetic layers. The direction of magnetization of the third ferromagnetic layer can be determined under an influence of spin-polarized electrons upon the third ferromagnetic layer by passing a current between the first and the second ferromagnetic layers.Type: GrantFiled: September 16, 2005Date of Patent: October 24, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Shigeru Haneda, Yuichi Ohsawa
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Patent number: 7126848Abstract: A magnetic cell includes a first magnetically fixed part including a laminated structure where a first ferromagnetic layer, a nonmagnetic layer and a second ferromagnetic layer are laminated, a second magnetically fixed part including a third ferromagnetic layer, a fourth ferromagnetic layer provided between the first and the second magnetically fixed parts, a first intermediate layer provided between the first magnetically fixed part and the fourth ferromagnetic layer, and a second intermediate layer provided between the second magnetically fixed part and the fourth ferromagnetic layer, a direction of magnetization of the fourth ferromagnetic layer being determined under an influence of spin-polarized electrons upon the fourth ferromagnetic layer by passing a current between the first and the second magnetically fixed parts.Type: GrantFiled: August 30, 2005Date of Patent: October 24, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Shiho Nakamura, Shigeru Haneda, Yuichi Ohsawa