Patents by Inventor Ryutaro YASUHARA

Ryutaro YASUHARA 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: 11889776
    Abstract: A variable resistance non-volatile memory element includes first and second electrodes and a variable resistance layer between the electrodes. The layer has a resistance value reversibly variable based on an electrical signal. The layer includes a first variable resistance layer that includes an oxygen deficient first metal oxide containing a first metal element and oxygen, and a second variable resistance layer that includes a composite oxide containing the first metal element, a second metal element different from the first metal element, and oxygen, and having a different degree of oxygen deficiency from the first metal oxide. The composite oxide has a lower degree of oxygen deficiency than the first metal oxide. At room temperature, the composite oxide has a smaller oxygen diffusion coefficient than a second metal oxide containing the first metal element and oxygen, and having the degree of oxygen deficiency equal to that of the composite oxide.
    Type: Grant
    Filed: June 23, 2021
    Date of Patent: January 30, 2024
    Assignee: Nuvoton Technology Corporation Japan
    Inventors: Ryutaro Yasuhara, Satoru Fujii, Takumi Mikawa, Atsushi Himeno, Kengo Nishio, Takehide Miyazaki, Hiroyuki Akinaga, Yasuhisa Naitoh, Hisashi Shima
  • Publication number: 20220198251
    Abstract: A semiconductor device includes variable resistance elements on a semiconductor substrate. Each of the variable resistance elements includes a first electrode, a second electrode, and a variable resistance layer that is sandwiched between the first electrode and the second electrode and that stores a resistance value that is continuously variable. The variable resistance layer includes a filament whose shape differs according to a neural network weight, and stores, as an analog value, the resistance value that is variable.
    Type: Application
    Filed: March 10, 2022
    Publication date: June 23, 2022
    Inventors: Takumi MIKAWA, Koji KATAYAMA, Ryutaro YASUHARA
  • Publication number: 20210408119
    Abstract: In a non-volatile storage device, a first lower-layer metal wire, a lower plug, a variable resistance element, an upper plug, and a first upper-layer metal wire are formed in that order from below in a storage region, and a second lower-layer metal wire, a first via, a middle-layer metal wire, a second via, and a second upper-layer metal wire are formed in that order from below in a circuit region. The first and second lower-layer metal wires are formed in the same layer, and the first and second upper-layer metal wires are formed on the same layer. Relative to a substrate, the variable resistance element and the middle-layer metal wire have top faces at different heights, bottom faces at different heights, or both top faces and bottom faces at different heights.
    Type: Application
    Filed: August 27, 2021
    Publication date: December 30, 2021
    Inventors: Atsushi HIMENO, Yukio HAYAKAWA, Koichi KAWASHIMA, Ryutaro YASUHARA
  • Publication number: 20210320248
    Abstract: A variable resistance non-volatile memory element includes first and second electrodes and a variable resistance layer between the electrodes. The layer has a resistance value reversibly variable based on an electrical signal. The layer includes a first variable resistance layer that includes an oxygen deficient first metal oxide containing a first metal element and oxygen, and a second variable resistance layer that includes a composite oxide containing the first metal element, a second metal element different from the first metal element, and oxygen, and having a different degree of oxygen deficiency from the first metal oxide. The composite oxide has a lower degree of oxygen deficiency than the first metal oxide. At room temperature, the composite oxide has a smaller oxygen diffusion coefficient than a second metal oxide containing the first metal element and oxygen, and having the degree of oxygen deficiency equal to that of the composite oxide.
    Type: Application
    Filed: June 23, 2021
    Publication date: October 14, 2021
    Inventors: Ryutaro YASUHARA, Satoru FUJII, Takumi MIKAWA, Atsushi HIMENO, Kengo NISHIO, Takehide MIYAZAKI, Hiroyuki AKINAGA, Yasuhisa NAITOH, Hisashi SHIMA
  • Patent number: 10490276
    Abstract: A non-volatile storage device includes: a first electrode; a second electrode; a variable resistance element including a variable resistance layer having a resistance value which changes according to a voltage pulse applied between the first and second electrodes; a voltage pulse application circuit which applies the voltage pulse between the first and second electrodes; and a control circuit which controls the voltage pulse application circuit. Upon receiving an external instruction, the control circuit: reads a current resistance state of the variable resistance element; and when the current resistance state is the high resistance state, causes the voltage pulse application circuit to apply a first additional voltage pulse having a first polarity between the electrodes; and when the current resistance state is the low resistance state, causes the voltage pulse application circuit to apply, between the electrodes, a second additional voltage pulse having a second polarity different from the first polarity.
    Type: Grant
    Filed: December 14, 2018
    Date of Patent: November 26, 2019
    Assignee: PANASONIC CORPORATION
    Inventor: Ryutaro Yasuhara
  • Publication number: 20190122731
    Abstract: A non-volatile storage device includes: a first electrode; a second electrode; a variable resistance element including a variable resistance layer having a resistance value which changes according to a voltage pulse applied between the first and second electrodes; a voltage pulse application circuit which applies the voltage pulse between the first and second electrodes; and a control circuit which controls the voltage pulse application circuit. Upon receiving an external instruction, the control circuit: reads a current resistance state of the variable resistance element; and when the current resistance state is the high resistance state, causes the voltage pulse application circuit to apply a first additional voltage pulse having a first polarity between the electrodes; and when the current resistance state is the low resistance state, causes the voltage pulse application circuit to apply, between the electrodes, a second additional voltage pulse having a second polarity different from the first polarity.
    Type: Application
    Filed: December 14, 2018
    Publication date: April 25, 2019
    Inventor: Ryutaro YASUHARA
  • Patent number: 8822972
    Abstract: A non-volatile memory element including a first electrode; a second electrode; and a variable resistance layer. The variable resistance layer including, when a first metal is M and a second metal is N: a third metal oxide layer NOz; a second metal oxide layer NOy; and a first metal oxide layer MOx such that the third, second and first metal oxide layers are stacked in this order; wherein when an oxygen content atomic percentage of an oxide of the first metal M in a stoichiometric state is A, an oxygen content atomic percentage of an oxide of the second metal N in a stoichiometric state is B, an oxygen content atomic percentage of MOx is C, an oxygen content atomic percentage of NOy is D, and an oxygen content atomic percentage of NOz is E, (D/B)<(C/A), (E/B)<(C/A) and y<z are satisfied.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: September 2, 2014
    Assignee: Panasonic Corporation
    Inventors: Ryutaro Yasuhara, Takeki Ninomiya, Takeshi Takagi
  • Publication number: 20140117305
    Abstract: A non-volatile memory element including a first electrode; a second electrode; and a variable resistance layer. The variable resistance layer including, when a first metal is M and a second metal is N, a third metal oxide layer NOz; a second metal oxide layer NOy; and a first metal oxide layer MOx such that the third, second and first metal oxide layers are stacked in this order; wherein when an oxygen content atomic percentage of an oxide of the first metal M in a stoichiometric state is A, an oxygen content atomic percentage of an oxide of the second metal N in a stoichiometric state is B, an oxygen content atomic percentage of MOx is C, an oxygen content atomic percentage of NOy is D, and an oxygen content atomic percentage of NOz is E, (D/B)<(C/A), (E/B)<(C/A) and y<z are satisfied.
    Type: Application
    Filed: September 26, 2013
    Publication date: May 1, 2014
    Applicant: PANASONIC CORPORATION
    Inventors: Ryutaro YASUHARA, Takeki NINOMIYA, Takeshi TAKAGI