Patents by Inventor Keiichi SAWA

Keiichi SAWA 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: 11974432
    Abstract: According to one embodiment, a semiconductor storage device includes a plurality of electrode films on a substrate, spaced from one another in a first direction. A charge storage film is provided on a side face the electrode films via a first insulating film. A semiconductor film is provided on a side face of the charge storage film via a second insulating film. The charge storage film includes a plurality of insulator regions contacting the first insulating film, a plurality of semiconductor or conductor regions provided between the insulator regions and another insulator region.
    Type: Grant
    Filed: August 26, 2021
    Date of Patent: April 30, 2024
    Assignee: Kioxia Corporation
    Inventors: Hiroyuki Yamashita, Yuta Saito, Keiichi Sawa, Kazuhiro Matsuo, Yuta Kamiya, Shinji Mori, Kota Takahashi, Junichi Kaneyama, Tomoki Ishimaru, Kenichiro Toratani, Ha Hoang, Shouji Honda, Takafumi Ochiai
  • Publication number: 20240074172
    Abstract: In one embodiment, a semiconductor storage device includes a lower electrode layer, a lower insulator, an upper electrode layer and an upper insulator along a first direction. The device further includes a first insulator provided on a side of a second direction of the upper electrode layer, and a second insulator provided between the upper electrode layer and the lower/upper/first insulator. The device further includes a charge storage layer, a third insulator and a semiconductor layer sequentially provided on a side of the second direction of the first insulator. A side face of the first insulator on a side of the upper electrode layer has a convex shape, the charge storage layer includes a first portion having a first thickness, and a second portion having a second thickness less than the first thickness, and the first portion is in contact with the first insulator.
    Type: Application
    Filed: March 10, 2023
    Publication date: February 29, 2024
    Applicant: Kioxia Corporation
    Inventors: Keiichi SAWA, Tomoyuki TAKEMOTO, Yuta KAMIYA, Hiroyuki YAMASHITA, Yuta SAITO, Tatsunori ISOGAI
  • Patent number: 11844219
    Abstract: A semiconductor device includes a semiconductor layer containing metal atoms, a charge storage layer provided on a surface of the semiconductor layer via a first insulating film, and an electrode layer provided on a surface of the charge storage layer via a second insulating film. The thickness of the first insulating film is 5 nm or more and 10 nm or less. The concentration of the metal atoms in the semiconductor layer is 5.0×1017 [EA/cm3] or higher and 1.3×1020 [EA/cm3] or lower.
    Type: Grant
    Filed: June 30, 2022
    Date of Patent: December 12, 2023
    Assignee: KIOXIA CORPORATION
    Inventors: Yuta Saito, Shinji Mori, Keiichi Sawa, Kazuhisa Matsuda, Kazuhiro Matsuo, Hiroyuki Yamashita
  • Publication number: 20230354596
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a plurality of U-shaped memory strings, each of the plurality of U-shaped memory strings including a first columnar body, a second columnar body, and a conductive connection body. The conductive connection body connects the first columnar body and the second columnar body. A plurality of first memory cells are connected in series in the first columnar body and are composed of a plurality of first conductive layers, a first inter-gate insulating film, a plurality of first floating electrodes, a first tunnel insulating film, and a first memory channel layer. The plurality of first floating electrodes are separated from the plurality of first conductive layers by the first inter-gate insulating film. A plurality of second memory cells are connected in series in the second columnar body, similally to the plurality of first memoriy cells.
    Type: Application
    Filed: June 30, 2023
    Publication date: November 2, 2023
    Applicant: Kioxia Corporation
    Inventor: Keiichi SAWA
  • Patent number: 11785774
    Abstract: In one embodiment, a semiconductor device includes a substrate, insulating films and first films alternately stacked on the substrate, at least one of the first films including an electrode layer and a charge storage layer provided on a face of the electrode layer via a first insulator, and a semiconductor layer provided on a face of the charge storage layer via a second insulator. The device further includes at least one of a first portion including nitrogen and provided between the first insulator and the charge storage layer with an air gap provided in the first insulator, a second portion including nitrogen, provided between the charge storage layer and the second insulator, and including a portion protruding toward the charge storage layer, and a third portion including nitrogen and provided between the second insulator and the semiconductor layer with an air gap provided in the first insulator.
    Type: Grant
    Filed: April 20, 2022
    Date of Patent: October 10, 2023
    Assignee: KIOXIA CORPORATION
    Inventors: Keiichi Sawa, Kazuhiro Matsuo, Kazuhisa Matsuda, Hiroyuki Yamashita, Yuta Saito, Shinji Mori, Masayuki Tanaka, Kenichiro Toratani, Atsushi Takahashi, Shouji Honda
  • Publication number: 20230309310
    Abstract: A semiconductor device of embodiments includes: a semiconductor layer containing silicon (Si); a first insulating layer provided in a first direction of the semiconductor layer; a second insulating layer surrounded by the semiconductor layer in a first cross section perpendicular to the first direction and containing silicon (Si) and oxygen (O); a third insulating layer surrounded by the second insulating layer in the first cross section and containing a metal element and oxygen (O); and a conductive layer surrounded by the first insulating layer in a second cross section perpendicular to the first direction, provided in the first direction of the third insulating layer, and spaced from the semiconductor layer.
    Type: Application
    Filed: September 9, 2022
    Publication date: September 28, 2023
    Applicant: Kioxia Corporation
    Inventors: Yuta SAITO, Shinji MORI, Hiroyuki YAMASHITA, Satoshi NAGASHIMA, Kazuhiro MATSUO, Kota TAKAHASHI, Shota KASHIYAMA, Keiichi SAWA, Junichi KANEYAMA
  • Patent number: 11751397
    Abstract: In one embodiment, a semiconductor storage device includes a stacked body in which a plurality of conducting layers are stacked through a plurality of insulating layers in a first direction, a semiconductor layer penetrating the stacked body, extending in the first direction and including metal atoms, and a memory film including a first insulator, a charge storage layer and a second insulator that are provided between the stacked body and the semiconductor layer. The semiconductor layer surrounds a third insulator penetrating the stacked body and extending in the first direction, and at least one crystal grain in the semiconductor layer has a shape surrounding the third insulator.
    Type: Grant
    Filed: June 27, 2022
    Date of Patent: September 5, 2023
    Assignee: Kioxia Corporation
    Inventors: Yuta Saito, Shinji Mori, Atsushi Takahashi, Toshiaki Yanase, Keiichi Sawa, Kazuhiro Matsuo, Hiroyuki Yamashita
  • Patent number: 11737262
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a plurality of U-shaped memory strings, each of the plurality of U-shaped memory strings including a first columnar body, a second columnar body, and a conductive connection body. The conductive connection body connects the first columnar body and the second columnar body. A plurality of first memory cells are connected in series in the first columnar body and are composed of a plurality of first conductive layers, a first inter-gate insulating film, a plurality of first floating electrodes, a first tunnel insulating film, and a first memory channel layer. The plurality of first floating electrodes are separated from the plurality of first conductive layers by the first inter-gate insulating film. A plurality of second memory cells are connected in series in the second columnar body, similarly to the plurality of first memory cells.
    Type: Grant
    Filed: April 7, 2021
    Date of Patent: August 22, 2023
    Assignee: Kioxia Corporation
    Inventor: Keiichi Sawa
  • Publication number: 20230200050
    Abstract: A semiconductor device of embodiments includes: a first electrode; a second electrode; an oxide semiconductor layer between the first electrode and the second electrode; a gate electrode surrounding the oxide semiconductor layer; a gate insulating layer between the gate electrode and the oxide semiconductor layer; a first insulating layer provided between the first electrode and the gate electrode; and a second insulating layer provided between the second electrode and the gate electrode. In a cross section parallel to a first direction from the first electrode to the second electrode, a first portion of the oxide semiconductor layer is provided between the gate insulating layer and the first electrode. In the cross section, a second portion of the oxide semiconductor layer is provided between the gate insulating layer and the second electrode.
    Type: Application
    Filed: June 15, 2022
    Publication date: June 22, 2023
    Applicant: Kioxia Corporation
    Inventors: Akifumi GAWASE, Ha HOANG, Atsuko SAKATA, Yuta KAMIYA, Kazuhiro MATSUO, Keiichi SAWA, Kota TAKAHASHI, Kenichiro TORATANI, Yimin LIU
  • Publication number: 20230090044
    Abstract: A semiconductor device of an embodiment includes a first electrode, a second electrode, a first oxide semiconductor layer between the first electrode and the second electrode, the first oxide semiconductor layer containing in, Zn, and a first metal element, and the first metal element being at least one metal of Ga, Mg, or Mn, a second oxide semiconductor layer between the first oxide semiconductor layer and the second electrode, the second oxide semiconductor layer containing In, Zn, and the first metal element, a third oxide semiconductor layer between the first oxide semiconductor layer and the second oxide semiconductor layer, the third oxide semiconductor layer containing in, Zn, and a second metal element, the second metal element being at least one metal of Al, Hf, La, Sn, Ta, Ti, W, Y, or Zr, a gate electrode facing the third oxide semiconductor layer, and a gate insulating.
    Type: Application
    Filed: March 4, 2022
    Publication date: March 23, 2023
    Applicant: Kioxia Corporation
    Inventors: Tomoki ISHIMARU, Shinji MORI, Kazuhiro MATSUO, Keiichi SAWA, Kenichiro TORATANI
  • Publication number: 20220336492
    Abstract: In one embodiment, a semiconductor storage device includes a stacked body in which a plurality of conducting layers are stacked through a plurality of insulating layers in a first direction, a semiconductor layer penetrating the stacked body, extending in the first direction and including metal atoms, and a memory film including a first insulator, a charge storage layer and a second insulator that are provided between the stacked body and the semiconductor layer. The semiconductor layer surrounds a third insulator penetrating the stacked body and extending in the first direction, and at least one crystal grain in the semiconductor layer has a shape surrounding the third insulator.
    Type: Application
    Filed: June 27, 2022
    Publication date: October 20, 2022
    Applicant: KIOXIA CORPORATION
    Inventors: Yuta SAITO, Shinji MORI, Atsushi TAKAHASHI, Toshiaki YANASE, Keiichi SAWA, Kazuhiro MATSUO, Hiroyuki YAMASHITA
  • Publication number: 20220336493
    Abstract: A semiconductor device includes a semiconductor layer containing metal atoms, a charge storage layer provided on a surface of the semiconductor layer via a first insulating film, and an electrode layer provided on a surface of the charge storage layer via a second insulating film. The thickness of the first insulating film is 5 nm or more and 10 nm or less. The concentration of the metal atoms in the semiconductor layer is 5.0×1017 [EA/cm3] or higher and 1.3×1020 [EA/cm3] or lower.
    Type: Application
    Filed: June 30, 2022
    Publication date: October 20, 2022
    Applicant: Kioxia Corporation
    Inventors: Yuta SAITO, Shinji MORI, Keiichi SAWA, Kazuhisa MATSUDA, Kazuhiro MATSUO, Hiroyuki YAMASHITA
  • Publication number: 20220302162
    Abstract: According to one embodiment, a semiconductor storage device includes a plurality of electrode films on a substrate, spaced from one another in a first direction. A charge storage film is provided on a side face the electrode films via a first insulating film. A semiconductor film is provided on a side face of the charge storage film via a second insulating film. The charge storage film includes a plurality of insulator regions contacting the first insulating film, a plurality of semiconductor or conductor regions provided between the insulator regions and another insulator region.
    Type: Application
    Filed: August 26, 2021
    Publication date: September 22, 2022
    Inventors: Hiroyuki Yamashita, Yuta Saito, Keiichi Sawa, Kazuhiro Matsuo, Yuta Kamiya, Shinji Mori, Kota Takahashi, Junichi Kaneyama, Tomoki Ishimaru, Kenichiro Toratani, Ha Hoang, Shouji Honda, Takafumi Ochiai
  • Publication number: 20220302160
    Abstract: According to one embodiment, a semiconductor storage device includes a plurality of electrode films on a substrate alternating with plurality of gaps or insulating layers. A charge storage film is provided on a side surface of each of the plurality of electrode films with a first insulating film placed therebetween. A semiconductor film is provided on a side surface of the charge storage film with a second insulating film placed therebetween. Furthermore, a concentration of a first element in the charge storage film adjacent to each gap or insulating film is higher than a concentration of the first element in the charge storage film adjacent to each electrode film. The first element is one of boron, niobium, or molybdenum.
    Type: Application
    Filed: August 24, 2021
    Publication date: September 22, 2022
    Inventors: Hiroyuki YAMASHITA, Keiichi SAWA, Yasushi NAKASAKI, Takamitsu ISHIHARA, Junichi KANEYAMA
  • Publication number: 20220262954
    Abstract: A semiconductor device of an embodiment includes a first electrode, a second electrode, a first metallic region provided between the first electrode and the second electrode and includes at least one metallic element selected from the group consisting of indium (In), gallium (Ga), zinc (Zn), aluminum (Al), magnesium (Mg), manganese (Mn), titanium (Ti), tungsten (W), molybdenum (Mo), and tin (Sn), a second metallic region provided between the first metallic region and the second electrode and includes the at least one metallic element, a semiconductor region provided between the first metallic region and the second metallic region and includes the at least one metallic element and oxygen (O), an insulating region provided between the first metallic region and the second metallic region and is surrounded by the semiconductor region, a gate electrode surrounding the semiconductor region, and a gate insulating layer provided between the semiconductor region and the gate electrode.
    Type: Application
    Filed: May 2, 2022
    Publication date: August 18, 2022
    Applicant: Kioxia Corporation
    Inventors: Tomoki ISHIMARU, Shinji MORI, Kazuhiro MATSUO, Keiichi SAWA, Akifumi GAWASE
  • Publication number: 20220246640
    Abstract: In one embodiment, a semiconductor device includes a substrate, insulating films and first films alternately stacked on the substrate, at least one of the first films including an electrode layer and a charge storage layer provided on a face of the electrode layer via a first insulator, and a semiconductor layer provided on a face of the charge storage layer via a second insulator. The device further includes at least one of a first portion including nitrogen and provided between the first insulator and the charge storage layer with an air gap provided in the first insulator, a second portion including nitrogen, provided between the charge storage layer and the second insulator, and including a portion protruding toward the charge storage layer, and a third portion including nitrogen and provided between the second insulator and the semiconductor layer with an air gap provided in the first insulator.
    Type: Application
    Filed: April 20, 2022
    Publication date: August 4, 2022
    Applicant: KIOXIA CORPORATION
    Inventors: Keiichi SAWA, Kazuhiro MATSUO, Kazuhisa MATSUDA, Hiroyuki YAMASHITA, Yuta SAITO, Shinji MORI, Masayuki TANAKA, Kenichiro TORATANI, Atsushi TAKAHASHI, Shouji HONDA
  • Patent number: 11404437
    Abstract: A semiconductor device includes a semiconductor layer containing metal atoms, a charge storage layer provided on a surface of the semiconductor layer via a first insulating film, and an electrode layer provided on a surface of the charge storage layer via a second insulating film. The thickness of the first insulating film is 5 nm or more and 10 nm or less. The concentration of the metal atoms in the semiconductor layer is 5.0×1017 [EA/cm3] or higher and 1.3×1020 [EA/cm3] or lower.
    Type: Grant
    Filed: August 14, 2020
    Date of Patent: August 2, 2022
    Assignee: KIOXIA CORPORATION
    Inventors: Yuta Saito, Shinji Mori, Keiichi Sawa, Kazuhisa Matsuda, Kazuhiro Matsuo, Hiroyuki Yamashita
  • Patent number: 11398494
    Abstract: In one embodiment, a semiconductor storage device includes a stacked body in which a plurality of conducting layers are stacked through a plurality of insulating layers in a first direction, a semiconductor layer penetrating the stacked body, extending in the first direction and including metal atoms, and a memory film including a first insulator, a charge storage layer and a second insulator that are provided between the stacked body and the semiconductor layer. The semiconductor layer surrounds a third insulator penetrating the stacked body and extending in the first direction, and at least one crystal grain in the semiconductor layer has a shape surrounding the third insulator.
    Type: Grant
    Filed: March 5, 2020
    Date of Patent: July 26, 2022
    Assignee: Kioxia Corporation
    Inventors: Yuta Saito, Shinji Mori, Atsushi Takahashi, Toshiaki Yanase, Keiichi Sawa, Kazuhiro Matsuo, Hiroyuki Yamashita
  • Patent number: 11349033
    Abstract: A semiconductor device of an embodiment includes a first electrode, a second electrode, a first metallic region provided between the first electrode and the second electrode and includes at least one metallic element selected from the group consisting of indium (In), gallium (Ga), zinc (Zn), aluminum (Al), magnesium (Mg), manganese (Mn), titanium (Ti), tungsten (W), molybdenum (Mo), and tin (Sn), a second metallic region provided between the first metallic region and the second electrode and includes the at least one metallic element, a semiconductor region provided between the first metallic region and the second metallic region and includes the at least one metallic element and oxygen (O), an insulating region provided between the first metallic region and the second metallic region and is surrounded by the semiconductor region, a gate electrode surrounding the semiconductor region, and a gate insulating layer provided between the semiconductor region and the gate electrode.
    Type: Grant
    Filed: September 16, 2020
    Date of Patent: May 31, 2022
    Assignee: Kioxia Corporation
    Inventors: Tomoki Ishimaru, Shinji Mori, Kazuhiro Matsuo, Keiichi Sawa, Akifumi Gawase
  • Patent number: 11335699
    Abstract: In one embodiment, a semiconductor device includes a substrate, insulating films and first films alternately stacked on the substrate, at least one of the first films including an electrode layer and a charge storage layer provided on a face of the electrode layer via a first insulator, and a semiconductor layer provided on a face of the charge storage layer via a second insulator. The device further includes at least one of a first portion including nitrogen and provided between the first insulator and the charge storage layer with an air gap provided in the first insulator, a second portion including nitrogen, provided between the charge storage layer and the second insulator, and including a portion protruding toward the charge storage layer, and a third portion including nitrogen and provided between the second insulator and the semiconductor layer with an air gap provided in the first insulator.
    Type: Grant
    Filed: December 29, 2020
    Date of Patent: May 17, 2022
    Assignee: KIOXIA CORPORATION
    Inventors: Keiichi Sawa, Kazuhiro Matsuo, Kazuhisa Matsuda, Hiroyuki Yamashita, Yuta Saito, Shinji Mori, Masayuki Tanaka, Kenichiro Toratani, Atsushi Takahashi, Shouji Honda