Patents by Inventor Yuko Yabe

Yuko Yabe 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: 9059402
    Abstract: A resistance-variable element as disclosed has high reliability, high densification, and good insulating properties. The device provides a resistance-variable element in which a first electrode including a metal primarily containing copper, an oxide film of valve-metal, an ion-conductive layer containing oxygen and a second electrode are laminated in this order.
    Type: Grant
    Filed: June 21, 2010
    Date of Patent: June 16, 2015
    Assignee: NEC CORPORATION
    Inventors: Munehiro Tada, Toshitsugu Sakamoto, Yuko Yabe, Yukishige Saito, Hiromitsu Hada
  • Patent number: 8766233
    Abstract: A semiconductor device includes at least first and second electrodes, and a layer including a transition metal oxide layer sandwiched between the first and second electrodes. The transition metal oxide layer includes first and second transition metal oxide layers formed of different first and second transition metals, respectively. The first transition metal oxide layer is provided on the first electrode side, the second transition metal oxide layer is provided on the second electrode side, the first transition metal oxide layer and the second transition metal oxide layer are in contact with each other, the first transition metal oxide layer has an oxygen concentration gradient from the interface between the first transition metal oxide layer and the second transition metal oxide layer toward the first electrode side, and the oxygen concentration at the interface is greater than the oxygen concentration on the first electrode side.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: July 1, 2014
    Assignee: NEC Corporation
    Inventors: Yukihiro Sakotsubo, Masayuki Terai, Munehiro Tada, Yuko Yabe, Yukishige Saito
  • Patent number: 8362456
    Abstract: To use a resistance change element having an MIM structure, which is obtained by stacking a metal, a metal oxide, and a metal, as a switching element, it is necessary to achieve OFF resistance higher than that required in a memory element by a factor of at least 1000. On the other hand, when a resistance change element is used as a memory element and when the difference between the ON resistance and the OFF resistance is a large value, high performance, for example, a short readout time, can be achieved. The present invention therefore provides a resistance change element capable of maintaining low ON resistance and achieving high OFF resistance. High OFF resistance can be achieved while low ON resistance is maintained by adding a second metal that is not contained in a metal oxide, which is a resistance change material, the second metal being capable of charge-compensating for metal deficiency or oxygen deficiency.
    Type: Grant
    Filed: March 21, 2008
    Date of Patent: January 29, 2013
    Assignee: NEC Corporation
    Inventors: Kimihiko Ito, Hiroshi Sunamura, Yuko Yabe
  • Publication number: 20120267598
    Abstract: A semiconductor device includes at least first and second electrodes, and a layer including a transition metal oxide layer sandwiched between the first and second electrodes. The transition metal oxide layer includes first and second transition metal oxide layers formed of different first and second transition metals, respectively. The first transition metal oxide layer is provided on the first electrode side, the second transition metal oxide layer is provided on the second electrode side, the first transition metal oxide layer and the second transition metal oxide layer are in contact with each other, the first transition metal oxide layer has an oxygen concentration gradient from the interface between the first transition metal oxide layer and the second transition metal oxide layer toward the first electrode side, and the oxygen concentration at the interface is greater than the oxygen concentration on the first electrode side.
    Type: Application
    Filed: October 4, 2010
    Publication date: October 25, 2012
    Applicant: NEC CORPORATION
    Inventors: Yukihiro Sakotsubo, Masayuki Terai, Munehiro Tada, Yuko Yabe, Yukishige Saito
  • Publication number: 20120091426
    Abstract: A resistance-variable element as disclosed has high reliability, high densification, and good insulating properties. The device provides a resistance-variable element in which a first electrode including a metal primarily containing copper, an oxide film of valve-metal, an ion-conductive layer containing oxygen and a second electrode are laminated in this order.
    Type: Application
    Filed: June 21, 2010
    Publication date: April 19, 2012
    Applicant: NEC CORPORATION
    Inventors: Munehiro Tada, Toshitsugu Sakamoto, Yuko Yabe, Yukishige Saito, Hiromitsu Hada
  • Publication number: 20100059730
    Abstract: To use a resistance change element having an MIM structure, which is obtained by stacking a metal, a metal oxide, and a metal, as a switching element, it is necessary to achieve OFF resistance higher than that required in a memory element by a factor of at least 1000. On the other hand, when a resistance change element is used as a memory element and when the difference between the ON resistance and the OFF resistance is a large value, high performance, for example, a short readout time, can be achieved. The present invention therefore provides a resistance change element capable of maintaining low ON resistance and achieving high OFF resistance. High OFF resistance can be achieved while low ON resistance is maintained by adding a second metal that is not contained in a metal oxide, which is a resistance change material, the second metal being capable of charge-compensating for metal deficiency or oxygen deficiency.
    Type: Application
    Filed: March 21, 2008
    Publication date: March 11, 2010
    Inventors: Kimihiko Ito, Hiroshi Sunamura, Yuko Yabe