Patents by Inventor Shosuke Fujii

Shosuke Fujii 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: 9147469
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array include the memory cells each including a variable resistance element in which a reset current flowing in a reset operation is smaller than a set current flowing in a set operation by not less than one order of magnitude. The control circuit performs the reset operation and the set operation for the memory cells. The control circuit performs the reset operation for all memory cells being in the low resistance state and connected to selected first interconnections and selected second interconnections.
    Type: Grant
    Filed: January 22, 2015
    Date of Patent: September 29, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira Takashima, Hidenori Miyagawa, Shosuke Fujii, Daisuke Matsushita
  • Publication number: 20150255479
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a semiconductor substrate, a first stacked layer structure including first to nth semiconductor layers (n is a natural number greater than or equal to 2) stacked in a first direction, and extending in a second direction, and first to nth memory cells provided on surfaces of the first to nth semiconductor layers facing a third direction. The ith memory cell (1?i?n) comprises a second stacked layer structure in which a first insulating layer, a charge storage layer, a second insulating layer, and a control gate electrode are stacked. The second insulating layer has an equivalent oxide thickness smaller than that of the first insulating layer.
    Type: Application
    Filed: September 18, 2014
    Publication date: September 10, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kiwamu SAKUMA, Masahiro KIYOTOSHI, Shosuke FUJII
  • Patent number: 9117848
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a fin structure stacked in order of a first oxide layer, a semiconductor layer and a second oxide layer in a first direction perpendicular to a surface of the semiconductor substrate, the fin structure extending in a second direction parallel to the surface of the semiconductor substrate, and a gate structure stacked in order of a gate oxide layer, a charge storage layer, a block insulating layer and a control gate electrode in a third direction perpendicular to the first and second directions from a surface of the semiconductor layer in the third direction.
    Type: Grant
    Filed: January 29, 2013
    Date of Patent: August 25, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Haruka Kusai, Kiwamu Sakuma, Masao Shingu, Shosuke Fujii, Masahiro Kiyotoshi
  • Patent number: 9099645
    Abstract: A resistance random access memory device according an embodiment includes a first electrode, a second electrode and a resistance change layer. The first electrode includes a metal. The resistance change layer is provided between the first electrode and the second electrode. One of the metal is able to reversibly move within the resistance change layer. The second electrode is formed of a material ionizing less easily than the metal. The resistance change layer contains silicon, oxygen, and nitrogen, a nitrogen concentration of the resistance change layer is less than 46 atomic % and not less than 20 atomic %.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: August 4, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidenori Miyagawa, Shosuke Fujii, Takayuki Ishikawa
  • Patent number: 9087715
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a fin-type stacked layer structure having memory cells, and a beam connected to an end portion of the structure. Each of the structure and the beam includes semiconductor layers stacked in a perpendicular direction. The beam includes a contact portion provided at one end of the beam, and a low resistance portion provided between the contact portion and the end portion of the structure.
    Type: Grant
    Filed: July 12, 2012
    Date of Patent: July 21, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Haruka Kusai, Kiwamu Sakuma, Shosuke Fujii, Masumi Saitoh, Masahiro Kiyotoshi
  • Patent number: 9082973
    Abstract: A resistance random access memory device according to an embodiment includes a first electrode, a second electrode, and a variable resistance portion placed between the first electrode and the second electrode. The variable resistance portion includes a first insulating layer, a second insulating layer, and a crystal layer that is placed between the first insulating layer and the second insulating layer, has a higher resistivity than the first electrode, and is crystalline.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: July 14, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Ishikawa, Shosuke Fujii, Hidenori Miyagawa, Hiroki Tanaka, Masumi Saitoh
  • Patent number: 9053786
    Abstract: According to one embodiment, a resistance-change memory includes a memory cell and a control circuit. The memory cell comprises first and second electrodes, and a variable resistance layer disposed between the first electrode and the second electrode. The control circuit applies a voltage between the first electrode and the second electrode to perform writing, erasing, and reading. During the writing, the control circuit applies a first voltage pulse between the first electrode and the second electrode, and then applies a second voltage pulse different in polarity from the first voltage pulse after applying the first voltage pulse.
    Type: Grant
    Filed: September 3, 2013
    Date of Patent: June 9, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Reika Ichihara, Daisuke Matsushita, Shosuke Fujii
  • Publication number: 20150155035
    Abstract: According to one embodiment, a resistance-change memory includes a memory cell and a control circuit. The memory cell comprises first and second electrodes, and a variable resistance layer disposed between the first electrode and the second electrode. The control circuit applies a voltage between the first electrode and the second electrode to perform writing, erasing, and reading. During the writing, the control circuit applies a first voltage pulse between the first electrode and the second electrode, and then applies a second voltage pulse different in polarity from the first voltage pulse after applying the first voltage pulse.
    Type: Application
    Filed: February 12, 2015
    Publication date: June 4, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Reika ICHIHARA, Daisuke MATSUSHITA, Shosuke FUJII
  • Patent number: 9040949
    Abstract: According to one embodiment, an information recording device includes first and second electrodes, a variable resistance layer between the first and second electrodes, and a control circuit which controls the variable resistance layer to n (n is a natural number except 1) kinds of resistance. The variable resistance layer comprises a material filled between the first and second electrodes, and particles arranged in a first direction from the first electrode to the second electrode in the material, and each of the particles has a resistance lower than that of the material. A resistance of the variable resistance layer is decided by a short between the first electrode and at least one of the particles.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: May 26, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuichiro Mitani, Daisuke Matsushita, Shosuke Fujii
  • Publication number: 20150131363
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array include the memory cells each including a variable resistance element in which a reset current flowing in a reset operation is smaller than a set current flowing in a set operation by not less than one order of magnitude. The control circuit performs the reset operation and the set operation for the memory cells. The control circuit performs the reset operation for all memory cells being in the low resistance state and connected to selected first interconnections and selected second interconnections.
    Type: Application
    Filed: January 22, 2015
    Publication date: May 14, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira TAKASHIMA, Hidenori MIYAGAWA, Shosuke FUJII, Daisuke MATSUSHITA
  • Patent number: 9024287
    Abstract: According to one embodiment, a memory device includes a first electrode, a second electrode and an insulating portion. The first electrode includes an ionizable metal. The second electrode includes a conductive material. The conductive material is more difficult to ionize than the metal. The insulating portion is provided between the first electrode and the second electrode. The insulating portion is made of an insulating material. A space is adjacent to a side surface of the insulating portion between the first electrode and the second electrode.
    Type: Grant
    Filed: August 7, 2014
    Date of Patent: May 5, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Ishikawa, Hiroki Tanaka, Shosuke Fujii
  • Publication number: 20150102279
    Abstract: According to one embodiment, a resistance change device includes a first electrode including a metal, a second electrode, and an amorphous oxide layer including Si and O between the first and second electrode, the layer having a concentration gradient of O and a first peak thereof in a direction from the first electrode to the second electrode.
    Type: Application
    Filed: November 21, 2014
    Publication date: April 16, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shosuke FUJII, Daisuke MATSUSHITA, Yuichiro MITANI
  • Patent number: 8987807
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes first to n-th semiconductor layers which are stacked in a first direction perpendicular to a surface of a semiconductor substrate and which extend in a second direction parallel to the surface of the semiconductor substrate, an electrode which extends in the first direction along side surfaces of the first to n-th semiconductor layers, the side surfaces of the first to n-th semiconductor layers exposing in a third direction perpendicular to the first and second directions, and first to n-th charge storage layers located between the first to n-th semiconductor layers and the electrode respectively. The first to n-th charge storage layers are separated from each other in areas between the first to n-th semiconductor layers.
    Type: Grant
    Filed: September 19, 2012
    Date of Patent: March 24, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shosuke Fujii, Kiwamu Sakuma, Jun Fujiki, Atsuhiro Kinoshita
  • Publication number: 20150078063
    Abstract: A semiconductor memory device according to an embodiment comprises a memory cell and a control circuit, the control circuit performing write of data to the memory cell. The memory cell includes a second resistance varying layer sandwiched between a first resistance varying layer and a third resistance varying layer. The second resistance varying layer has a resistance value which is smaller than that of the other resistance varying layers. The control circuit applies to the memory cell a first voltage pulse, and then applies to the memory cell a second voltage pulse that has a rise time which is shorter than that of the first voltage pulse.
    Type: Application
    Filed: July 28, 2014
    Publication date: March 19, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Reika ICHIHARA, Shosuke FUJII, Hidenori MIYAGAWA, Takayuki ISHIKAWA
  • Publication number: 20150076439
    Abstract: According to one embodiment, a memory device includes a first electrode, a second electrode and a variable resistance layer. The second electrode includes a metal. The metal is more easily ionizable than a material of the first electrode. The variable resistance layer is disposed between the first electrode and the second electrode. The variable resistance layer includes a first layer and a second layer. The first layer has a relatively high crystallization rate. The second layer contacts the first layer. The second layer has a relatively low crystallization rate. The first layer and the second layer are stacked along a direction connecting the first electrode and the second electrode.
    Type: Application
    Filed: July 30, 2014
    Publication date: March 19, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masumi SAITOH, Takayuki ISHIKAWA, Shosuke FUJII, Hidenori MIYAGAWA, Chika TANAKA, Ichiro MIZUSHIMA
  • Publication number: 20150076440
    Abstract: According to one embodiment, a memory device includes a first electrode, a second electrode and an insulating portion. The first electrode includes an ionizable metal. The second electrode includes a conductive material. The conductive material is more difficult to ionize than the metal. The insulating portion is provided between the first electrode and the second electrode. The insulating portion is made of an insulating material. A space is adjacent to a side surface of the insulating portion between the first electrode and the second electrode.
    Type: Application
    Filed: August 7, 2014
    Publication date: March 19, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Takayuki ISHIKAWA, Hiroki Tanaka, Shosuke Fujii
  • Patent number: 8981461
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a fin-type stacked layer structure in which a first insulating layer, a first semiconductor layer, . . . an n-th insulating layer, an n-th semiconductor layer, and an (n+1)-th insulating layer (n is a natural number equal to or more than 2) are stacked in order thereof in a first direction perpendicular to a surface of a semiconductor substrate and which extends in a second direction parallel to the surface of the semiconductor substrate, first to n-th memory strings which use the first to n-th semiconductor layers as channels respectively, a common semiconductor layer which combines the first to n-th semiconductor layers at first ends of the first to n-th memory strings in the second direction.
    Type: Grant
    Filed: September 19, 2012
    Date of Patent: March 17, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shosuke Fujii, Daisuke Hagishima, Kiwamu Sakuma
  • Patent number: 8975611
    Abstract: According to one embodiment, a nonvolatile variable resistance device includes a first electrode, a second electrode, a first layer, and a second layer. The second electrode includes a metal element. The first layer is arranged between the first electrode and the second electrode and includes a semiconductor element. The second layer is inserted between the second electrode and the first layer and includes the semiconductor element. The percentage of the semiconductor element being unterminated is higher in the second layer than in the first layer.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: March 10, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Yamauchi, Shosuke Fujii, Reika Ichihara
  • Patent number: 8971106
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array include the memory cells each including a variable resistance element in which a reset current flowing in a reset operation is smaller than a set current flowing in a set operation by not less than one order of magnitude. The control circuit performs the reset operation and the set operation for the memory cells. The control circuit performs the reset operation for all memory cells being in the low resistance state and connected to selected first interconnections and selected second interconnections.
    Type: Grant
    Filed: September 8, 2014
    Date of Patent: March 3, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Takashima, Hidenori Miyagawa, Shosuke Fujii, Daisuke Matsushita
  • Publication number: 20140376303
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array include the memory cells each including a variable resistance element in which a reset current flowing in a reset operation is smaller than a set current flowing in a set operation by not less than one order of magnitude. The control circuit performs the reset operation and the set operation for the memory cells. The control circuit performs the reset operation for all memory cells being in the low resistance state and connected to selected first interconnections and selected second interconnections.
    Type: Application
    Filed: September 8, 2014
    Publication date: December 25, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira TAKASHIMA, Hidenori Miyagawa, Shosuke Fujii, Daisuke Matsushita