Patents by Inventor Masahiko Nakayama

Masahiko Nakayama 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: 20150325785
    Abstract: According to one embodiment, a magnetoresistive element is disclosed. The magnetoresistive element includes a reference layer, a tunnel barrier layer, a storage layer. The storage layer includes a first region and a second region provided outside the first region to surround the first region, the second region including element included in the first region and another element being different from the element. The magnetoresistive element further includes a cap layer including a third region and a fourth region provided outside the third region to surround the third region, the fourth region including an element included in the third region and the another element.
    Type: Application
    Filed: July 23, 2015
    Publication date: November 12, 2015
    Inventors: Masahiko NAKAYAMA, Masatoshi YOSHIKAWA, Tadashi KAI, Yutaka HASHIMOTO, Masaru TOKO, Hiroaki YODA, Jae Geun OH, Keum Bum LEE, Choon Kun RYU, Hyung Suk LEE, Sook Joo KIM
  • Patent number: 9184374
    Abstract: According to one embodiment, a magnetoresistive element includes first, second and third magnetic layers, and first and second nonmagnetic layers. The third magnetic layer has stack layers including a first stack layer close to the second magnetic layer, and a second stack layer far from the second magnetic layer. Each of the first and second stack layers includes a first layer made of a ferromagnetic material and a second layer made of a nonmagnetic material, and a first ratio of a film thickness of the first layer to that of the second layer in the first stack layer is higher than a second ratio of a film thickness of the first layer to that of the second layer in the second stack layer.
    Type: Grant
    Filed: August 9, 2013
    Date of Patent: November 10, 2015
    Inventors: Kazuya Sawada, Toshihiko Nagase, Youngmin Eeh, Koji Ueda, Daisuke Watanabe, Masahiko Nakayama, Tadashi Kai, Hiroaki Yoda
  • Patent number: 9178134
    Abstract: According to one embodiment, a magnetoresistive element is disclosed. The element includes a first magnetic film, a second magnetic film, and a first nonmagnetic layer formed between the first magnetic film and the second magnetic film. The second magnetic film includes a first magnetic layer formed on a side of the first nonmagnetic layer, a second magnetic layer formed on a side opposite to the first nonmagnetic layer, and a second nonmagnetic layer formed between the first magnetic layer and the second magnetic layer and containing TiN.
    Type: Grant
    Filed: March 10, 2014
    Date of Patent: November 3, 2015
    Inventors: Masahiko Nakayama, Tadashi Kai, Masaru Toko, Toshihiko Nagase, Hiroaki Yoda
  • Patent number: 9166151
    Abstract: A magnetoresistive element has a magnetic layer, an insulating layer and a magnetic layer, which are laminated on a base electrode, and side walls of the magnetic layers that are formed when the magnetic layers are processed. At least one element selected from the group of consisting He, C, N, O, F, Ne, Ti, V, Cu, Al, Si, P, S, Cl, Ar, Ge, As, Kr, Zr, In, Sn, Sb, Pb and Bi is injected into the side walls and edge portions of the magnetic layers to improve the magnetic characteristics of the first and second magnetic layers.
    Type: Grant
    Filed: February 26, 2013
    Date of Patent: October 20, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akiyuki Murayama, Masahiko Nakayama, Satoshi Seto, Tatsuya Kishi, Masaru Toko
  • Publication number: 20150263271
    Abstract: According to one embodiment, there is provided a magnetoresistive element, including a lower electrode having crystallinity on a substrate, a first conductive layer including an amorphous state on the lower electrode, a buffer layer on the first conductive layer, and an MTJ element on the buffer layer.
    Type: Application
    Filed: September 5, 2014
    Publication date: September 17, 2015
    Inventors: Makoto NAGAMINE, Youngmin EEH, Koji UEDA, Daisuke WATANABE, Kazuya SAWADA, Toshihiko NAGASE, Masahiko NAKAYAMA
  • Patent number: 9123879
    Abstract: According to one embodiment, a magnetoresistive element is disclosed. The magnetoresistive element includes a reference layer, a tunnel barrier layer, a storage layer. The storage layer includes a first region and a second region provided outside the first region to surround the first region, the second region including element included in the first region and another element being different from the element. The magnetoresistive element further includes a cap layer including a third region and a fourth region provided outside the third region to surround the third region, the fourth region including an element included in the third region and the another element.
    Type: Grant
    Filed: March 10, 2014
    Date of Patent: September 1, 2015
    Inventors: Masahiko Nakayama, Masatoshi Yoshikawa, Tadashi Kai, Yutaka Hashimoto, Masaru Toko, Hiroaki Yoda, Jae Geun Oh, Keum Bum Lee, Choon Kun Ryu, Hyung Suk Lee, Sook Joo Kim
  • Patent number: 9076960
    Abstract: A magnetic memory element includes a memory layer having magnetic anisotropy on the film surface thereof in the perpendicular direction and in which the magnetization direction is variable, a reference layer having magnetic anisotropy on the film surface thereof in the perpendicular direction and in which the magnetization direction is not variable, and a tunnel barrier layer which is interposed between the memory layer and the reference layer. The memory layer is made of an alloy including cobalt (Co) andiron (Fe). A plurality of oxygen atoms are present on both interfaces of the memory layer.
    Type: Grant
    Filed: September 3, 2013
    Date of Patent: July 7, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiko Nakayama, Tatsuya Kishi, Masaru Toko, Akiyuki Murayama, Yutaka Hashimoto, Hisanori Aikawa
  • Publication number: 20150069557
    Abstract: According to one embodiment, a magnetoresistive element is disclosed. The magnetoresistive element includes a reference layer, a tunnel barrier layer, a storage layer. The storage layer includes a first region and a second region provided outside the first region to surround the first region, the second region including element included in the first region and another element being different from the element. The magnetoresistive element further includes a cap layer including a third region and a fourth region provided outside the third region to surround the third region, the fourth region including an element included in the third region and the another element.
    Type: Application
    Filed: March 10, 2014
    Publication date: March 12, 2015
    Inventors: Masahiko NAKAYAMA, Masatoshi YOSHIKAWA, Tadashi KAI, Yutaka HASHIMOTO, Masaru TOKO, Hiroaki YODA, Jae Geun OH, Keum Bum LEE, Choon Kun RYU, Hyung Suk LEE, Sook Joo KIM
  • Publication number: 20150069558
    Abstract: According to one embodiment, a magnetic memory is disclosed. The memory includes a conductive layer containing a first metal material, a stacked body above the conductive layer, and including a first magnetization film containing a second metal material, a second magnetization film, and a tunnel barrier layer between the first magnetization film and the second magnetization film, and an insulating layer on a side face of the stacked body, and containing an oxide of the first metal material. The first magnetization film and/or the second magnetization film includes a first region positioned in a central portion, and a second region positioned in an edge portion and containing As, P, Ge, Ga, Sb, In, N, Ar, He, F, Cl, Br, I, Si, B, C, O, Zr, Tb, S, Se, or Ti.
    Type: Application
    Filed: March 10, 2014
    Publication date: March 12, 2015
    Inventors: Masahiko NAKAYAMA, Tadashi KAI, Masaru TOKO, Hiroaki YODA, Hyung Suk LEE, Jae Geun OH, Choon Kun RYU, Min Suk LEE
  • Publication number: 20150069548
    Abstract: According to one embodiment, a magnetoresistive element includes a storage layer having a variable magnetization direction, a reference layer having an invariable magnetization direction, a tunnel barrier layer formed between the storage layer and the reference layer, and a heater layer formed on an opposite side to the tunnel barrier layer of the storage layer. The storage layer includes a first layer formed on a side of the heater layer, and a second layer formed on the side of the tunnel barrier layer and having a Curie temperature higher than that of the first layer.
    Type: Application
    Filed: March 7, 2014
    Publication date: March 12, 2015
    Inventors: Masahiko NAKAYAMA, Tadashi KAI, Hiroaki YODA
  • Publication number: 20150069555
    Abstract: According to one embodiment, a magnetic memory includes first and second magnetoresistive effect elements neighboring in a first direction in a cell array of a substrate, each of the first and second magnetoresistive effect elements including a first magnetic layer with an invariable direction of magnetization, a second magnetic layer with a variable direction of magnetization, and a nonmagnetic layer between the first magnetic layer and the second magnetic layer. Directions of magnetization of the first magnetic layers of the first and second magnetoresistive effect elements are different from each other.
    Type: Application
    Filed: March 7, 2014
    Publication date: March 12, 2015
    Inventors: Shintaro SAKAI, Masahiko NAKAYAMA
  • Publication number: 20150069551
    Abstract: According to one embodiment, a magnetoresistive element is disclosed. The magnetoresistive element includes a reference layer. The reference layer includes a first region, and a second region provided outside the first region to surround the same. The second region contains an element contained in the first region and another element being different from the element. The magnetoresistive element further includes a storage layer, and a tunnel barrier layer provided between the reference layer and the storage layer. The storage layer is free from the another element.
    Type: Application
    Filed: March 7, 2014
    Publication date: March 12, 2015
    Inventors: Masaru TOKO, Masahiko NAKAYAMA, Kuniaki SUGIURA, Yutaka HASHIMOTO, Tadashi KAI, Akiyuki MURAYAMA, Tatsuya KISHI
  • Publication number: 20150069552
    Abstract: According to one embodiment, a magnetic memory device includes a magnetoresistance effect element having a structure in which a first magnetic layer, a nonmagnetic layer, a second magnetic layer, and a third magnetic layer are stacked, wherein the third magnetic layer comprises a first region and a plurality of second regions, and each of the second regions is surrounded by the first region, has conductivity, and has a greater magnetic property than the first region.
    Type: Application
    Filed: March 7, 2014
    Publication date: March 12, 2015
    Inventors: Yutaka HASHIMOTO, Tadashi KAI, Masahiko NAKAYAMA, Hiroaki YODA, Toshihiko NAGASE, Masatoshi YOSHIKAWA, Yasuyuki SONODA
  • Publication number: 20150069554
    Abstract: According to one embodiment, a magnetic memory is disclosed. The memory includes a conductive layer containing a first metallic material, a stacked body formed above the conductive layer and including a first magnetic layer containing a second metallic material, a second magnetic layer, and a tunnel barrier layer formed between the first magnetic layer and the second magnetic layer, and an insulating layer formed on a side face of the stacked body and containing an oxide of the first metallic material. A standard electrode potential of the first metallic material is lower than the standard electrode potential of the second metallic material.
    Type: Application
    Filed: March 7, 2014
    Publication date: March 12, 2015
    Inventors: Masahiko NAKAYAMA, Yasuyuki SONODA, Hiroaki YODA, Makoto NAGAMINE, Masatoshi YOSHIKAWA, Masaru TOKO, Tadashi KAI, Daisuke WATANABE, Youngmin EEH, Koji UEDA, Kazuya SAWADA, Toshihiko NAGASE
  • Publication number: 20150061053
    Abstract: According to one embodiment, a magnetoresistive element is disclosed. The element includes a first magnetic film, a second magnetic film, and a first nonmagnetic layer formed between the first magnetic film and the second magnetic film. The second magnetic film includes a first magnetic layer formed on a side of the first nonmagnetic layer, a second magnetic layer formed on a side opposite to the first nonmagnetic layer, and a second nonmagnetic layer formed between the first magnetic layer and the second magnetic layer and containing TiN.
    Type: Application
    Filed: March 10, 2014
    Publication date: March 5, 2015
    Inventors: Masahiko NAKAYAMA, Tadashi KAI, Masaru TOKO, Toshihiko NAGASE, Hiroaki YODA
  • Publication number: 20150063014
    Abstract: According to one embodiment, a magnetic memory includes a cell array includes a plurality of memory cells, each memory cell including a magnetoresistive effect element; and a read circuit to read data from a memory cell selected based on an address signal from among the memory cells. The read circuit selects one determination level from among a plurality of determination levels corresponding to a position of a magnetoresistive effect element in the cell array and uses the selected determination level to perform reading of the data.
    Type: Application
    Filed: March 7, 2014
    Publication date: March 5, 2015
    Inventors: Shintaro SAKAI, Masahiko NAKAYAMA
  • Patent number: 8958239
    Abstract: One embodiment provides a magnetic memory element, including: a first ferromagnetic layer whose magnetization is variable; a second ferromagnetic layer which has a first band split into a valence band and a conduction band and a second band being continuous at least from the valence band to the conduction band; and a nonmagnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: February 17, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoaki Inokuchi, Takao Marukame, Mizue Ishikawa, Hideyuki Sugiyama, Masahiko Nakayama, Tatsuya Kishi, Hiroaki Yoda, Yoshiaki Saito
  • Patent number: 8897060
    Abstract: According to one embodiment, a magnetoresistance effect element includes first and second magnetic layers having an axis of easy magnetization in a direction perpendicular to a film surface, a first nonmagnetic layer formed between the first and second magnetic layers, a first interface magnetic layer formed between the first magnetic layer and the first nonmagnetic layer, and a second nonmagnetic layer formed in the first interface magnetic layer and having an amorphous structure. An electric current flowing through the first magnetic layer, the first nonmagnetic layer, and the second magnetic layer makes a magnetization direction in the first magnetic layer variable.
    Type: Grant
    Filed: March 28, 2012
    Date of Patent: November 25, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiko Nakayama, Katsuya Nishiyama
  • Patent number: 8884389
    Abstract: According to one embodiment, a magnetoresistive element comprises a first magnetic layer having a magnetization direction invariable and perpendicular to a film surface, a tunnel barrier layer formed on the first magnetic layer, and a second magnetic layer formed on the tunnel barrier layer and having a magnetization direction variable and perpendicular to the film surface. The first magnetic layer includes an interface layer formed on an upper side in contact with a lower portion of the tunnel barrier layer, and a main body layer formed on a lower side and serving as an origin of perpendicular magnetic anisotropy. The interface layer includes a first area provided on an inner side and having magnetization, and a second area provided on an outer side to surround the first area and having magnetization smaller than the magnetization of the first area or no magnetization.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: November 11, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masaru Toko, Masahiko Nakayama, Akihiro Nitayama, Tatsuya Kishi, Hisanori Aikawa, Hiroaki Yoda
  • Patent number: 8878321
    Abstract: According to one embodiment, a magnetoresistive element comprises a first magnetic layer, in which a magnetization direction is variable and is perpendicular to a film surface, a tunnel barrier layer that is formed on the first magnetic layer, and a second magnetic layer that is formed on the tunnel barrier layer, a magnetization direction of the second magnetic layer being variable and being perpendicular to the film surface. The second magnetic layer comprises a body layer that constitutes an origin of perpendicular magnetic anisotropy, and an interface layer that is formed between the body layer and the tunnel barrier layer. The interface layer has a permeability higher than that of the body layer and a planar size larger than that of the body layer.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hisanori Aikawa, Hiroaki Yoda, Masahiko Nakayama, Tatsuya Kishi, Sumio Ikegawa