Patents by Inventor Yukio Hayakawa

Yukio Hayakawa 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: 20130178042
    Abstract: Provided is a method for manufacturing a variable resistance element, the method including: forming a first electrode material layer above a substrate; forming a first tantalum oxide material layer; forming a second tantalum oxide material layer; forming a second electrode material layer; and annealing at least the first tantalum oxide material layer after forming the first tantalum oxide material layer and before forming the second electrode material layer, wherein an oxygen content percentage of one of the first tantalum oxide material layer and the second tantalum oxide material layer is higher than an oxygen content percentage of the other.
    Type: Application
    Filed: January 30, 2012
    Publication date: July 11, 2013
    Inventors: Takeki Ninomiya, Yukio Hayakawa, Takumi Mikawa, Takeshi Takagi
  • Patent number: 8482958
    Abstract: Provided is a current steering element that can prevent write didturb even when an electrical pulse with different polarities is applied and that can cause a large current to flow through a variable resistance element. The current steering element includes a first electrode (32), a second electrode (31), and a current steering layer (33). The current steering layer (33) comprises SiNx (where 0<x?0.85) added with hydrogen or fluorine. When D (D=D0×1022 atoms/cm3) represents a density of hydrogen or fluorine, d (nm) represents a thickness of the current steering layer (33), and V0 (V) represents a maximum value applicable to between the first electrode (32) and the second electrode (31), D, x, d, and V0 satisfy the following Formulae. (ln(10000(C·exp(?·d)exp(?·x))?1)?)2?V0 (ln(1000(C·exp(?·d)exp(?·x))?1)?)2?(ln(10000(C·exp(?·d)exp(?·x))?1)?)2/2?0 wherein C=k1×D0k2, and ?, ?, ?, k1, and k2 are constants.
    Type: Grant
    Filed: March 10, 2011
    Date of Patent: July 9, 2013
    Assignee: Panasonic Corporation
    Inventors: Yukio Hayakawa, Koji Arita, Takumi Mikawa, Takeki Ninomiya
  • Patent number: 8481990
    Abstract: A variable resistance nonvolatile memory element capable of suppressing a variation in resistance values is provided.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: July 9, 2013
    Assignee: Panasonic Corporation
    Inventors: Yoshio Kawashima, Takumi Mikawa, Yukio Hayakawa
  • Publication number: 20130171799
    Abstract: A current steering element (100) formed such that the current steering element covers a lower opening (105) of a via hole (104) formed in an interlayer insulating layer (102), comprises: a corrosion-suppressing layer (106) formed on a lower side of a lower opening of the via hole such that the corrosion-suppressing layer covers an entire portion of the lower opening; a second electrode layer (108) formed under the corrosion-suppressing layer and comprising a material different from a material of the corrosion-suppressing layer; a current steering layer (110) formed under the second electrode layer such that the current steering layer is physically in contact with the second electrode layer; and a first electrode layer (112) formed under the current steering layer such that the first electrode layer is physically in contact with the current steering layer; and the first electrode layer, the current steering layer and the second electrode layer constitute one of a MSM diode and a MIM diode.
    Type: Application
    Filed: September 16, 2011
    Publication date: July 4, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Ryoko Miyanaga, Takumi Mikawa, Yukio Hayakawa, Takeki Ninomiya, Koji Arita
  • Publication number: 20130128654
    Abstract: A nonvolatile memory element includes a current steering element which bidirectionally rectifies current in response to applied voltage and a variable resistance element connected in series with the current steering element. The current steering element includes an MSM diode and an MSM diode which are connected in series and each of which bidirectionally rectifies current in response to applied voltage. The MSM diode and the MSM diode include a lower electrode, a first current steering layer, a first metal layer, a second current steering layer, and an upper electrode which are stacked in this order. The current steering element has a breakdown current which is larger than an initial breakdown current which flows in the variable resistance element at the time of initial breakdown.
    Type: Application
    Filed: June 7, 2012
    Publication date: May 23, 2013
    Inventors: Shinichi Yoneda, Yukio Hayakawa, Kiyotaka Tsuji
  • Publication number: 20130119344
    Abstract: A variable resistance nonvolatile storage element includes: a first electrode; a second electrode; and a variable resistance layer having a resistance value that reversibly changes based on an electrical signal applied between the electrodes, wherein the variable resistance layer has a structure formed by stacking a first transition metal oxide layer, a second transition metal oxide layer, and a third transition metal oxide layer in this order, the first transition metal oxide layer having a composition expressed as MOx (where M is a transition metal and O is oxygen), the second transition metal oxide layer having a composition expressed as MOy (where x>y), and the third transition metal oxide layer having a composition expressed as MOz (where y>z).
    Type: Application
    Filed: October 6, 2011
    Publication date: May 16, 2013
    Inventors: Takumi Mikawa, Yukio Hayakawa, Takeki Ninomiya, Yoshio Kawashima, Shinichi Yoneda
  • Publication number: 20130112935
    Abstract: A nonvolatile memory element according to the present invention includes a first metal line; a plug formed on the first metal line and connected to the first metal line; a stacked structure including a first electrode, a second electrode, and a variable resistance layer, the stacked structure being formed on a plug which is connected to the first electrode; a second metal line formed on the stacked structure and directly connected to the second electrode; and a side wall protective layer which covers the side wall of the stacked structure and has an insulating property and an oxygen barrier property, wherein part of a lower surface of the second metal line is located under an upper surface of the stacked structure.
    Type: Application
    Filed: November 30, 2011
    Publication date: May 9, 2013
    Inventors: Atsushi Himeno, Haruyuki Sorada, Yukio Hayakawa, Takumi Mikawa
  • Patent number: 8437173
    Abstract: A nonvolatile memory element which can be initialized at low voltage includes a variable resistance layer (116) located between a lower electrode (105) and an upper electrode (107) and having a resistance value that reversibly changes based on electrical signals applied between these electrodes. The variable resistance layer (116) includes at least two layers: a first variable resistance layer (1161) including a first transition metal oxide (116b); and a second variable resistance layer (1162) including a second transition metal oxide (116a) and a third transition metal oxide (116c). The second transition metal oxide (116a) has an oxygen deficiency higher than either oxygen deficiency of the first transition metal oxide (116b) or the third transition metal oxide (116c), and the second transition metal oxide (116a) and the third transition metal oxide (116c) are in contact with the first variable resistance layer (1161).
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: May 7, 2013
    Assignee: Panasonic Corporation
    Inventors: Yukio Hayakawa, Takumi Mikawa, Yoshio Kawashima, Takeki Ninomiya
  • Patent number: 8369161
    Abstract: A semiconductor device includes an insulation layer (14) provided on a semiconductor substrate (12), a p-type semiconductor region (16) provided on the insulation layer, an isolation region (18) provided that surrounds the p-type semiconductor region to reach the insulation layer, an n-type source region (20) and an n-type drain region (22) provided on the p-type semiconductor region, a charge storage region (30) provided above the p-type semiconductor region between the n-type source region and the n-type drain region, and an voltage applying portion that applies a different voltage to the p-type semiconductor region while any of programming, erasing and reading a different data of a memory cell that has the charge storage region is being preformed.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: February 5, 2013
    Assignee: Spansion LLC
    Inventor: Yukio Hayakawa
  • Publication number: 20130015423
    Abstract: Provided is a method for manufacturing a variable resistance nonvolatile semiconductor memory element, and a nonvolatile semiconductor memory element which make it possible to operate at a low voltage and high speed when initial breakdown is caused, and exhibit favorable diode element characteristics. The method for manufacturing the nonvolatile semiconductor memory element includes, after forming a top electrode of a variable resistance element and at least before forming a top electrode of an MSM diode element, oxidizing to insulate a portion of a variable resistance film in a region around an end face of a variable resistance layer.
    Type: Application
    Filed: November 18, 2011
    Publication date: January 17, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Takumi Mikawa, Yukio Hayakawa, Yoshio Kawashima, Takeki Ninomiya
  • Publication number: 20130010529
    Abstract: A nonvolatile memory element includes a variable resistance layer located between a lower electrode and an upper electrode and having a resistance value that reversibly changes based on electrical signals applied between these electrodes. The variable resistance layer includes at least two layers: a first variable resistance layer including a first transition metal oxide; and a second variable resistance layer including a second transition metal oxide and a transition metal compound. The second transition metal oxide has an oxygen content atomic percentage lower than an oxygen content atomic percentage of the first transition metal oxide, the transition metal compound contains either oxygen and nitrogen or oxygen and fluorine, and the second transition metal oxide and the transition metal compound are in contact with the first variable resistance layer.
    Type: Application
    Filed: November 24, 2011
    Publication date: January 10, 2013
    Inventors: Yukio Hayakawa, Takumi Mikawa, Takeki Ninomiya
  • Publication number: 20130001504
    Abstract: Provided is a nonvolatile memory element which inhibits deterioration of a oxygen concentration profile of a variable resistance layer due to a thermal budget and is able to stably operate at low voltages, and a method for manufacturing the nonvolatile memory element. A nonvolatile memory element (12) includes a first electrode layer (105) formed above a substrate (100), a variable resistance layer (106) disposed on the first electrode layer (105), and a second electrode layer (107) disposed on the variable resistance layer (106), and the variable resistance layer (106) has a two-layer structure in which a oxygen- and/or nitrogen-deficient tantalum oxynitride layer (106a) and a tantalum oxide layer (106b) are stacked.
    Type: Application
    Filed: November 18, 2011
    Publication date: January 3, 2013
    Inventors: Takeki Ninomiya, Takumi Mikawa, Yukio Hayakawa
  • Publication number: 20120326113
    Abstract: Provided are a non-volatile memory element which can reduce a voltage of an electric pulse required for initial breakdown, and can lessen non-uniformity of a resistance value of the non-volatile memory element, and a non-volatile memory device including the non-volatile memory element.
    Type: Application
    Filed: June 9, 2011
    Publication date: December 27, 2012
    Inventors: Shinichi Yoneda, Takumi Mikawa, Yukio Hayakawa, Takeki Ninomiya
  • Publication number: 20120309138
    Abstract: The present invention provides a semiconductor device that has a shorter distance between the bit lines and easily achieves higher storage capacity and density, and a method of manufacturing such a semiconductor device. The semiconductor device includes: first bit lines formed on a substrate; an insulating layer that is provided between the first bit lines on the substrate, and has a higher upper face than the first bit lines; channel layers that are provided on both side faces of the insulating layer, and are coupled to the respective first bit lines; and charge storage layers that are provided on the opposite side faces of the channel layers from the side faces on which the insulating layers are formed.
    Type: Application
    Filed: August 10, 2012
    Publication date: December 6, 2012
    Inventors: Yukio HAYAKAWA, Hiroyuki NANSEI
  • Patent number: 8318566
    Abstract: Devices and methods for isolating adjacent charge accumulation layers in a semiconductor device are disclosed. In one embodiment, a semiconductor device comprises a bit line formed in a semiconductor substrate, a charge accumulation layer formed on the semiconductor substrate, a word line formed on the charge accumulation layer across the bit line, and a channel region formed in the semiconductor substrate below the word line and between the bit line and its adjacent bit line. For the semiconductor device, the charge accumulation layer is formed above the channel region in a widthwise direction of the word line, and a width of the word line is set to be narrower than a distance between an end of the channel region and a central part of the channel region in a lengthwise direction of the word line.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: November 27, 2012
    Assignee: Spansion LLC
    Inventors: Fumihiko Inoue, Haruki Souma, Yukio Hayakawa
  • Publication number: 20120252184
    Abstract: A variable resistance element comprises, when M is a transition metal element, O is oxygen, and x and y are positive numbers satisfying y>x; a lower electrode; a first oxide layer formed on the lower electrode and comprising MOx when a content ratio of O with respect to M is x; a second oxide layer formed on the first oxide layer and comprising MOy when a content ratio of O with respect to M is y; an upper electrode formed on the second oxide layer; a protective layer formed on the upper electrode and comprising an electrically conductive material having a composition different from a composition of the upper electrode; an interlayer insulating layer formed to cover the protective layer; and an upper contact plug formed inside an upper contact hole penetrating the interlayer insulating layer.
    Type: Application
    Filed: December 14, 2010
    Publication date: October 4, 2012
    Inventors: Takeki Ninomiya, Yoshio Kawashima, Yukio Hayakawa, Takumi Mikawa
  • Publication number: 20120238055
    Abstract: An object of the present invention is to provide a method for manufacturing a variable resistance nonvolatile semiconductor memory element which can operate at a low voltage and high speed when initial breakdown is caused, and inhibit oxidization of a contact plug. The method for manufacturing the variable resistance nonvolatile semiconductor memory element, which includes a bottom electrode, a variable resistance layer, and a top electrode which are formed above a contact plug, includes oxidizing to insulate an end portion of the variable resistance layer prior to forming a bottom electrode by patterning a first conductive film.
    Type: Application
    Filed: November 10, 2011
    Publication date: September 20, 2012
    Inventors: Takumi Mikawa, Yukio Hayakawa, Takeki Ninomiya, Yoshio Kawashima
  • Patent number: 8264029
    Abstract: The present invention provides a semiconductor device that has a shorter distance between the bit lines and easily achieves higher storage capacity and density, and a method of manufacturing such a semiconductor device. The semiconductor device includes: first bit lines formed on a substrate; an insulating layer that is provided between the first bit lines on the substrate, and has a higher upper face than the first bit lines; channel layers that are provided on both side faces of the insulating layer, and are coupled to the respective first bit lines; and charge storage layers that are provided on the opposite side faces of the channel layers from the side faces on which the insulating layers are formed.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: September 11, 2012
    Assignee: Spansion LLC
    Inventors: Yukio Hayakawa, Hiroyuki Nansei
  • Publication number: 20120199805
    Abstract: Provided are a nonvolatile memory device which can suppress non-uniformity in initial breakdown voltages among nonvolatile memory elements and prevent reduction of yield, and a manufacturing method thereof. The nonvolatile memory device includes a nonvolatile memory element (108) having a stacked-layer structure in which a resistance variable layer (106) is parallel to a main surface of a substrate (117) and is planarized, and a plug (103) electrically connected to either a first electrode (105) or a second electrode (107), and an area of an end surface of a plug (103) at which the plug (103) and the nonvolatile memory element (108) are connected together, the end surface being parallel to the main surface of the substrate (117), is greater than a cross-sectional area of a cross-section of a first transition metal oxide layer (115) which is an electrically-conductive region, the cross-section being parallel to the main surface of the substrate (117).
    Type: Application
    Filed: August 11, 2011
    Publication date: August 9, 2012
    Inventors: Haruyuki Sorada, Takeki Ninomiya, Takumi Mikawa, Yukio Hayakawa
  • Publication number: 20120112153
    Abstract: Provided is a nonvolatile memory device which requires a lower initializing voltage such that the nonvolatile memory device can be operated at a low voltage. The nonvolatile memory device (10) includes: a first electrode layer (105) formed above a semiconductor substrate (100); a first oxygen-deficient tantalum oxide layer (106x) formed on the first electrode layer (105) and having a composition represented by TaOx where 0.8?x?1.9; a second oxygen-deficient tantalum oxide layer (106y) formed on the first oxygen-deficient tantalum oxide layer (106x) and having a composition represented by TaOy where 2.1?y; and a second electrode layer (107) formed on the second tantalum oxide layer (106y). The second tantalum oxide layer (106y) has a pillar structure including a plurality of pillars.
    Type: Application
    Filed: July 13, 2011
    Publication date: May 10, 2012
    Inventors: Takeki Ninomiya, Satoru Fujii, Yukio Hayakawa, Takumi Mikawa