Patents by Inventor Masayuki Sagoi

Masayuki Sagoi 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).

  • Patent number: 7593193
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: September 22, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Patent number: 7345852
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Grant
    Filed: March 6, 2006
    Date of Patent: March 18, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Publication number: 20070297101
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Application
    Filed: August 30, 2007
    Publication date: December 27, 2007
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Patent number: 7140096
    Abstract: A method of manufacturing a magnetoresistance effect device, including: forming a first ferromagnetic body, a nonmagnetic dielectric layer on the first ferromagnetic body, and a second ferromagnetic body on the nonmagnetic dielectric layer; etching part of an external region of a predetermined ferromagnetic tunnel junction region using a first linear mask pattern which is traversing the predetermined ferromagnetic tunnel junction region; and etching another part of the external region of the predetermined ferromagnetic tunnel junction region using a second linear mask pattern which is traversing the predetermined ferromagnetic tunnel junction region and intersecting with the first linear mask pattern.
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: November 28, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuya Kishi, Shigeki Takahashi, Kentaro Nakajima, Minoru Amano, Masayuki Sagoi, Yoshiaki Saito
  • Publication number: 20060146451
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Application
    Filed: March 6, 2006
    Publication date: July 6, 2006
    Applicant: KABUSHI KAISHA TOSHIBA
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Patent number: 7038894
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: May 2, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Patent number: 7035137
    Abstract: A semiconductor memory device comprises word lines, bit lines, memory cells, a row decoder, a column decoder, and a write circuit. The word lines are formed along a first direction. The bit lines are formed along a second direction. Memory cells include magneto-resistive elements and are arranged at intersections of the word lines and the bit lines. The row decoder selects at least one of the word lines. The column decoder selects at least one of the bit lines. The write circuit supplies first and second write currents to a selected word line and selected bit line respectively and writes data into a selected memory cell arranged at the intersection of the selected word line and the selected bit line. The write circuit changes the current values of the first and second write currents according to a temperature change.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: April 25, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshihisa Iwata, Kentaro Nakajima, Masayuki Sagoi, Yuui Shimizu
  • Patent number: 6995962
    Abstract: There is provided a magnetoresistance effect element including a first pinned ferromagnetic layer, a second pinned ferromagnetic layer facing the first pinned ferromagnetic layer, surface regions of the first and second pinned ferromagnetic layer facing each other being different from each other in composition, a free ferromagnetic layer intervening between the first and second pinned ferromagnetic layers, a first tunnel barrier layer intervening between the first pinned ferromagnetic layer and the free ferromagnetic layer, and a second tunnel barrier layer intervening between the second pinned ferromagnetic layer and the free ferromagnetic layer.
    Type: Grant
    Filed: October 20, 2004
    Date of Patent: February 7, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Masayuki Sagoi, Minoru Amano, Kentaro Nakajima, Shigeki Takahashi, Tatsuya Kishi
  • Patent number: 6987653
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: January 17, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Publication number: 20050185347
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Application
    Filed: April 21, 2005
    Publication date: August 25, 2005
    Applicant: KABUSHI KAISHA TOSHIBA
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Publication number: 20050078418
    Abstract: There is provided a magnetoresistance effect element including a first pinned ferromagnetic layer, a second pinned ferromagnetic layer facing the first pinned ferromagnetic layer, surface regions of the first and second pinned ferromagnetic layer facing each other being different from each other in composition, a free ferromagnetic layer intervening between the first and second pinned ferromagnetic layers, a first tunnel barrier layer intervening between the first pinned ferromagnetic layer and the free ferromagnetic layer, and a second tunnel barrier layer intervening between the second pinned ferromagnetic layer and the free ferromagnetic layer.
    Type: Application
    Filed: October 20, 2004
    Publication date: April 14, 2005
    Inventors: Yoshiaki Saito, Masayuki Sagoi, Minoru Amano, Kentaro Nakajima, Shigeki Takahashi, Tatsuya Kishi
  • Publication number: 20050078417
    Abstract: Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The manufacturing method uses two linear mask patterns intersecting with each other to form sharp corners of a ferromagnetic tunnel junction. An electron beam (EB) drawing may be used to form the S-shape plane.
    Type: Application
    Filed: July 25, 2003
    Publication date: April 14, 2005
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tatsuya Kishi, Shigeki Takahashi, Kentaro Nakajima, Minoru Amano, Masayuki Sagoi, Yoshiaki Saito
  • Patent number: 6868002
    Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: March 15, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
  • Publication number: 20050036362
    Abstract: A semiconductor memory device comprises word lines, bit lines, memory cells, a row decoder, a column decoder, and a write circuit. The word lines are formed along a first direction. The bit lines are formed along a second direction. Memory cells include magneto-resistive elements and are arranged at intersections of the word lines and the bit lines. The row decoder selects at least one of the word lines. The column decoder selects at least one of the bit lines. The write circuit supplies first and second write currents to a selected word line and selected bit line respectively and writes data into a selected memory cell arranged at the intersection of the selected word line and the selected bit line. The write circuit changes the current values of the first and second write currents according to a temperature change.
    Type: Application
    Filed: March 24, 2004
    Publication date: February 17, 2005
    Inventors: Yoshihisa Iwata, Kentaro Nakajima, Masayuki Sagoi, Yuui Shimizu
  • Patent number: 6839206
    Abstract: There is provided a magnetoresistance effect element including a first pinned ferromagnetic layer, a second pinned ferromagnetic layer facing the first pinned ferromagnetic layer, surface regions of the first and second pinned ferromagnetic layer facing each other being different from each other in composition, a free ferromagnetic layer intervening between the first and second pinned ferromagnetic layers, a first tunnel barrier layer intervening between the first pinned ferromagnetic layer and the free ferromagnetic layer, and a second tunnel barrier layer intervening between the second pinned ferromagnetic layer and the free ferromagnetic layer.
    Type: Grant
    Filed: March 11, 2002
    Date of Patent: January 4, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Masayuki Sagoi, Minoru Amano, Kentaro Nakajima, Shigeki Takahashi, Tatsuya Kishi
  • Publication number: 20040175596
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Application
    Filed: March 11, 2004
    Publication date: September 9, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Publication number: 20040156231
    Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.
    Type: Application
    Filed: February 5, 2004
    Publication date: August 12, 2004
    Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
  • Patent number: 6751074
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: June 15, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Publication number: 20040109349
    Abstract: A magnetic memory device includes first wirings which run in the first direction and are divided in the second direction different from the first direction, a second wiring which runs in the second direction, and a first magneto-resistive element which is arranged across the first divided wirings near the intersection of the first and second wirings in the first memory cell region.
    Type: Application
    Filed: September 12, 2003
    Publication date: June 10, 2004
    Inventors: Kentaro Nakajima, Yoshiaki Asao, Keiji Hosotani, Masayuki Sagoi
  • Patent number: 6730949
    Abstract: A magnetoresistance effect devices having a magnetization free layer free to rotate in an applied magnetic field. The magnetization free layer may include first and second ferromagnetic material layers with a nonmagnetic material layer disposed between the two ferromagnetic material layers. Those ferromagnetic materials are antiferromagnetically coupled with each other at a magnetic coupling field J (−3 [kOe]≦J<0 [kOe]) or ferromagnetically coupled with each other. Alternatively, the magnetization free film includes a first ferromagnetic material layer including a center region having a first magnetization and edge regions having a second magnetization different from the first magnetization and a second ferromagnetic material layer including a center region having a third magnetization parallel to the first magnetization and edge regions having a fourth magnetization different from the third magnetization.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: May 4, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuya Kishi, Minoru Amano, Yoshiaki Saito, Shigeki Takahashi, Kentaro Nakajima, Masayuki Sagoi