Patents by Inventor Takashi Takenaga

Takashi Takenaga 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).

  • Publication number: 20100270633
    Abstract: Ferromagnetic layers have magnetizations oriented to such directions as to cancel each other, so that the net magnetization of the ferromagnetic layers is substantially zero. That is, the ferromagnetic layers are exchange-coupled with a nonmagnetic layer interposed therebetween, thereby forming an SAF structure. Since the net magnetization of the ferromagnetic layers forming the SAF structure is substantially zero, the magnetization of a recording layer is determined by the magnetization of a ferromagnetic layer. Therefore, the ferromagnetic layer is made of a CoFeB alloy having high uniaxial magnetic anisotropy, and the ferromagnetic layers are made of a CoFe alloy having a high exchange-coupling force.
    Type: Application
    Filed: July 6, 2010
    Publication date: October 28, 2010
    Applicant: Renesas Technology Corp.
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Taisuke Furukawa, Masakazu Taki
  • Publication number: 20100254182
    Abstract: A magnetic storage device which enables stable operation at the time of recording information into MRAM and the stable retention of recorded information. The die of the magnetic storage device has a substrate, first and second wirings, a magnetic storage element and a first magnetic shielding structure. The first magnetic shielding structure is formed to cover the magnetic storage element in a plan view. Second and third magnetic shielding structures sandwich the die in a thickness direction. A lead frame member has the die mounted thereon and contains a ferromagnetic material. The lead frame member overlaps with only part of the die in a plan view.
    Type: Application
    Filed: March 22, 2010
    Publication date: October 7, 2010
    Inventors: Takeharu KUROIWA, Masayoshi Tarutani, Takashi Takenaga, Hiroshi Takada
  • Patent number: 7786725
    Abstract: A magnetic field detection apparatus capable of changing the detection range and detection sensitivity as desired for a specific application is disclosed. A magnetoresistance effect element is applied a bias magnetic field and an external magnetic field. The bias magnetic field and the external magnetic field are generated on the same straight line, and therefore the bias magnetic field functions to hamper the external magnetic field applied to the magnetoresistance effect element. Thus, the magnetization of the free layer of the magnetoresistance effect element is suppressed, and the rotational angle of the magnetized vector is reduced. As a result, the characteristic of the resistance value of the magnetoresistance effect element to the external magnetic field is shifted by an amount equivalent to the bias magnetic field.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: August 31, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventors: Taisuke Furukawa, Hiroshi Kobayashi, Takashi Takenaga, Takeharu Kuroiwa, Sadeh Beysen, Masakazu Taki
  • Patent number: 7773408
    Abstract: Ferromagnetic layers have magnetizations oriented to such directions as to cancel each other, so that the net magnetization of the ferromagnetic layers is substantially zero. That is, the ferromagnetic layers are exchange-coupled with a nonmagnetic layer interposed therebetween, thereby forming an SAF structure. Since the net magnetization of the ferromagnetic layers forming the SAF structure is substantially zero, the magnetization of a recording layer is determined by the magnetization of a ferromagnetic layer. Therefore, the ferromagnetic layer is made of a CoFeB alloy having high uniaxial magnetic anisotropy, and the ferromagnetic layers are made of a CoFe alloy having a high exchange-coupling force.
    Type: Grant
    Filed: November 17, 2006
    Date of Patent: August 10, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Taisuke Furukawa, Masakazu Taki
  • Publication number: 20100156405
    Abstract: A magnetic field detection device including a magnetic body (magnetic flux guide) provided for adjusting a magnetic field to be applied to a magneto-resistance element. A shape of an on-substrate magnetic body in plan view is a tapered shape on one end portion side and a substantially funnel shape on another end portion side opposite the one end portion, the another end portion being larger in width than the one end portion, and a magneto-resistance element is disposed in front of an output-side end portion. In the on-substrate magnetic body, a contour of a tapered portion is not linear like a funnel, but has a curved shape in which a first curved portion protruding outward with a gentle curvature and a second curved portion protruding inward with a curvature similar to that of the first curved portion are continuously formed.
    Type: Application
    Filed: May 27, 2008
    Publication date: June 24, 2010
    Applicant: Mitsubishi Electric Corporation
    Inventors: Taisuke Furukawa, Takeharu Kuroiwa, Shingo Tomohisa, Takashi Takenaga, Masakazu Taki, Hiroshi Takada, Yuji Abe
  • Publication number: 20100151276
    Abstract: A magnetic storage device stable in write characteristic is provided. A first nonmagnetic film is provided over a recording layer. A first ferromagnetic film is provided over the first nonmagnetic film and has a first magnetization and a first film thickness. A second nonmagnetic film is provided over the first ferromagnetic film. A second ferromagnetic film is provided over the second nonmagnetic film, is coupled in antiparallel with the first ferromagnetic film, and has a second magnetization and a second film thickness. An antiferromagnetic film is provided over the second ferromagnetic film. The sum of the product of the first magnetization and the first film thickness and the product of the second magnetization and the second film thickness is smaller than the product of the magnetization of the recording layer and the film thickness of the recording layer.
    Type: Application
    Filed: November 12, 2009
    Publication date: June 17, 2010
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Ryoji Matsuda, Yosuke Takeuchi
  • Patent number: 7733210
    Abstract: A magnetic field detector includes: a magnet; a detecting magnetic resistance element having a layer structure containing a ferromagnetic layer, the resistance being changed when a direction of magnetization of the ferromagnetic layer is changed; and a reference magnetic resistance element having substantially the same layer structure as that of the detecting magnetic resistance element. A magnetic field, the magnetic intensity of which is higher than the saturation magnetic field, is impressed by the magnet in a direction which is sensed by the ferromagnetic layer of the reference magnetic resistance element.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: June 8, 2010
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Taisuke Furukawa, Hiroshi Kobayashi, Takashi Takenaga, Takeharu Kuroiwa, Beysen Sadeh, Masakazu Taki
  • Publication number: 20090302404
    Abstract: A semiconductor device having an MTJ device excellent in operating characteristics and a manufacturing method therefor are obtained. The MTJ device is formed of a laminated structure obtained by laminating a lower magnetic film, a tunnel insulating film, and an upper magnetic film in this order. The lower magnetic film and the upper magnetic film contain noncrystalline or microcrystalline ferrocobalt boron (CoFeB) as a constituent material. The tunnel insulating film contains aluminum oxide (AlOx) as a constituent material. A CAP layer is formed over the upper magnetic film of the MTJ device and a hard mask is formed over the CAP layer. The CAP layer contains a simple substance of crystalline ruthenium (Ru) as a constituent material and the hard mask contains a simple substance of crystalline tantalum (Ta) as a constituent material. The hard mask is so formed that the film thickness thereof is larger than the film thickness of the CAP layer.
    Type: Application
    Filed: May 11, 2009
    Publication date: December 10, 2009
    Inventors: Ryoji Matsuda, Shuichi Ueno, Haruo Furuta, Takashi Takenaga, Takeharu Kuroiwa
  • Publication number: 20090273965
    Abstract: Ferromagnetic layers (18, 22) have magnetizations oriented to such directions as to cancel each other, so that the net magnetization of the ferromagnetic layers (18, 22) is substantially zero. That is, the ferromagnetic layers (18, 22) are exchange-coupled with a nonmagnetic layer (20) interposed therebetween, thereby forming an SAF structure. Since the net magnetization of the ferromagnetic layers (18, 22) forming the SAF structure is substantially zero, the magnetization of a recording layer (RL) is determined by the magnetization of a ferromagnetic layer (14). Therefore, the ferromagnetic layer (14) is made of a CoFeB alloy having high uniaxial magnetic anisotropy, and the ferromagnetic layers (18, 22) are made of a CoFe alloy having a high exchange-coupling force.
    Type: Application
    Filed: November 17, 2006
    Publication date: November 5, 2009
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Taisuke Furukawa, Masakazu Taki
  • Publication number: 20090261435
    Abstract: A magnetic memory element having a layer structure containing a fixing layer (pinned layer: PL) having a magnetization direction fixed unidirectionally, a nonmagnetic dielectric layer (TN1) in contact with the fixing layer (PL), and a memory layer (free layer: FL) having a first surface in contact with the nonmagnetic dielectric layer (TN1) and a second surface on the opposite to the first surface, the magnetization direction of the memory layer (FL) having a reversible magnetization direction in response to the current through the layer structure. The entire surface of the first surface of the memory layer (FL) is covered with the nonmagnetic dielectric layer (TN1) and in the joint surface of the nonmagnetic dielectric layer (TN1) and the fixing layer (PL), the first surface of the nonmagnetic dielectric layer (TN1) is exposed in a manner of surrounding the joint surface.
    Type: Application
    Filed: April 21, 2009
    Publication date: October 22, 2009
    Inventors: Hiroshi TAKADA, Takashi TAKENAGA, Takeharu KUROIWA, Taisuke FURUKAWA
  • Publication number: 20090250776
    Abstract: There is provided a magnetic memory device stable in write characteristics. The magnetic memory device has a recording layer. The planar shape of the recording layer has the maximum length in the direction of the easy-axis over a primary straight line along the easy-axis, and is situated over a length smaller than the half of the maximum length in the direction perpendicular to the easy-axis, and on the one side and on the other side of the primary straight line respectively, the planar shape has a first part situated over a length in the direction perpendicular to the easy-axis, and a second part situated over a length smaller than the length in the direction perpendicular to the easy-axis. The outer edge of the first part includes only a smooth curve convex outwardly of the outer edge.
    Type: Application
    Filed: March 6, 2009
    Publication date: October 8, 2009
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Shuichi Ueno, Kiyoshi Kawabata
  • Patent number: 7508203
    Abstract: A magnetic field detector having a reference magnetoresistive element and a magnetic field detecting magnetoresistive element. The reference magnetoresistive element and the magnetic field detecting magnetoresistive element each has a stack structure including an antiferromagnetic layer, a fixed layer of a ferromagnetic material with the direction of magnetization fixed by the antiferromagnetic layer, a nonmagnetic layer, and a free layer of a ferromagnetic material with the direction of magnetization adapted to be changed by an external magnetic field. The reference magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are parallel or antiparallel to each other, and the magnetic field detecting magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are different from each other.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: March 24, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takashi Takenaga, Hiroshi Kobayashi, Takeharu Kuroiwa, Sadeh Beysen, Taisuke Furukawa
  • Publication number: 20080186635
    Abstract: A magnetic field detector having a reference magnetoresistive element and a magnetic field detecting magnetoresistive element. The reference magnetoresistive element and the magnetic field detecting magnetoresistive element each has a stack structure including an antiferromagnetic layer, a fixed layer of a ferromagnetic material with the direction of magnetization fixed by the antiferromagnetic layer, a nonmagnetic layer, and a free layer of a ferromagnetic material with the direction of magnetization adapted to be changed by an external magnetic field. The reference magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are parallel or antiparallel to each other, and the magnetic field detecting magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are different from each other.
    Type: Application
    Filed: April 4, 2008
    Publication date: August 7, 2008
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takashi TAKENAGA, Hiroshi Kobayashi, Takeharu Kuroiwa, Sadeh Beysen, Taisuke Furukawa
  • Publication number: 20080168649
    Abstract: A photolithographic process using an X-direction delimiting mask (S11) for aligning respective side faces of a TMR element (1) and a strap (5) situated in a negative X side is performed, to shape the TMR element (1) and the strap (5) into desired configurations. The X-direction delimiting mask (S11) includes a straight edge and is disposed such that the straight edge is parallel to a Y direction and crosses both the TMR element (1) and the strap (5) in plan view. In use of the X-direction delimiting mask (S11), respective portions of the TMR element (1) and the strap (5) situated in a positive X side relative to the straight edge in plan view are covered with the X-direction delimiting mask (S11).
    Type: Application
    Filed: March 14, 2008
    Publication date: July 17, 2008
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventors: Shinroku Maejima, Shuichi Ueno, Takashi Takenaga, Takeharu Kuroiwa
  • Patent number: 7375516
    Abstract: A magnetic field detector having a reference magnetoresistive element and a magnetic field detecting magnetoresistive element. The reference magnetoresistive element and the magnetic field detecting magnetoresistive element each has a stack structure including an antiferromagnetic layer, a fixed layer of a ferromagnetic material with the direction of magnetization fixed by the antiferromagnetic layer, a nonmagnetic layer, and a free layer of a ferromagnetic material with the direction of magnetization adapted to be changed by an external magnetic field. The reference magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are parallel or antiparallel to each other, and the magnetic field detecting magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are different from each other.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: May 20, 2008
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takashi Takenaga, Hiroshi Kobayashi, Takeharu Kuroiwa, Sadeh Beysen, Taisuke Furukawa
  • Publication number: 20070165334
    Abstract: A magnetic field detector having a reference magnetoresistive element and a magnetic field detecting magnetoresistive element. The reference magnetoresistive element and the magnetic field detecting magnetoresistive element each has a stack structure including an antiferromagnetic layer, a fixed layer of a ferromagnetic material with the direction of magnetization fixed by the antiferromagnetic layer, a nonmagnetic layer, and a free layer of a ferromagnetic material with the direction of magnetization adapted to be changed by an external magnetic field. The reference magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are parallel or antiparallel to each other, and the magnetic field detecting magnetoresistive element is such that the direction of magnetization of the fixed layer and the direction of magnetization of the free layer in the nonmagnetic field are different from each other.
    Type: Application
    Filed: September 22, 2004
    Publication date: July 19, 2007
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takashi Takenaga, Hiroshi Kobayashi, Takeharu Kuroiwa, Sadeh Beysen, Taisuke Furukawa
  • Publication number: 20070069849
    Abstract: A magnetic field detector includes: a magnet; a magnetic resistance element used for detection having a layer structure containing a ferromagnetic layer, the resistance being changed when a direction of magnetization of the ferromagnetic layer is changed; and a magnetic resistance element used for reference having the substantially same layer structure as that of the magnetic resistance element used for detection, wherein a magnetic field, the magnetic intensity of which is higher than the saturation magnetic field, is impressed by the magnet in the direction which is felt by the ferromagnetic layer of the magnetic resistance element used for reference.
    Type: Application
    Filed: March 20, 2006
    Publication date: March 29, 2007
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Taisuke Furukawa, Hiroshi Kobayashi, Takashi Takenaga, Takeharu Kuroiwa, Beysen Sadeh, Masakazu Taki
  • Publication number: 20070047152
    Abstract: A magnetic field detection apparatus capable of changing the detection range and detection sensitivity as desired for a specific application is disclosed. A magnetoresistance effect element is applied a bias magnetic field and an external magnetic field. The bias magnetic field and the external magnetic field are generated on the same straight line, and therefore the bias magnetic field functions to hamper the external magnetic field applied to the magnetoresistance effect element. Thus, the magnetization of the free layer of the magnetoresistance effect element is suppressed, and the rotational angle of the magnetized vector is reduced. As a result, the characteristic of the resistance value of the magnetoresistance effect element to the external magnetic field is shifted by an amount equivalent to the bias magnetic field.
    Type: Application
    Filed: August 25, 2006
    Publication date: March 1, 2007
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Taisuke Furukawa, Hiroshi Kobayashi, Takashi Takenaga, Takeharu Kuroiwa, Sadeh Beysen, Masakazu Taki
  • Patent number: 7167906
    Abstract: In the information communication system wherein communication is performed between a server and a terminal apparatus via the Internet, the system includes an access server AS for recognizing an access point that has been used for a communication between the server and the terminal apparatus, and a www server that transmits information indicating the recognized access point with respect to the terminal apparatus, and the terminal apparatus includes a processing part for executing a control according to the information indicating the access point which has been transmitted on.
    Type: Grant
    Filed: October 2, 2002
    Date of Patent: January 23, 2007
    Assignees: Pioneer Corporation, Increment P. Corporation
    Inventor: Takashi Takenaga
  • Publication number: 20060267058
    Abstract: In a ferromagnetic tunnel junction element, a recording layer is in a circular shape, which can suppress an increase in magnetization switching field due to miniaturization of the element. Further, the recording layer includes a first ferromagnetic layer, a first non-magnetic layer, a second ferromagnetic layer, a second non-magnetic layer, and a third ferromagnetic layer successively stacked. The first and second ferromagnetic layers, and the second and third ferromagnetic layers are coupled antiparallel to each other, so that it is possible to control the magnetization distribution of the recording layer in an approximately single direction.
    Type: Application
    Filed: May 30, 2006
    Publication date: November 30, 2006
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Kobayashi, Sadeh Beysen