Patents by Inventor Shigeto Oota

Shigeto Oota 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: 8194467
    Abstract: A nonvolatile semiconductor memory device includes: a memory unit; and a control unit. The memory unit includes: a multilayer structure including electrode films and interelectrode insulating films alternately stacked; a semiconductor pillar piercing the multilayer structure; insulating films and a memory layer provided between the electrode films and the semiconductor pillar; and a wiring connected to the semiconductor pillar. In an erase operation, the control unit performs: a first operation setting the wiring at a first potential and the electrode film at a second potential lower than the first potential during a first period; and a second operation setting the wiring at a third potential and the electrode film at a fourth potential lower than the third potential during a second period after the first operation. A length of the second period is shorter than the first period, and/or a difference between the third and fourth potentials is smaller than a difference between the first and second potentials.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: June 5, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimasa Mikajiri, Ryouhei Kirisawa, Masaru Kito, Shigeto Oota
  • Patent number: 8188530
    Abstract: A semiconductor memory device provided with a cell array section and a peripheral circuit section, the device includes: a back gate electrode; a stacked body provided on the back gate electrode; a plurality of semiconductor pillars extending in a stacking direction; connection members, each of the connection members connecting one of the semiconductor pillars to another one of the semiconductor pillars; a back-gate electrode contact applying a potential to the back gate electrode; a gate electrode provided in the peripheral circuit section; and a gate electrode contact applying a potential to the gate electrode, the back gate electrode and the gate electrode respectively including: a lower semiconductor layer; a conductive layer provided on the lower semiconductor layer; and an upper semiconductor layer provided on the conductive layer, the connection members being provided in or on the upper semiconductor layer, the back-gate electrode contact and the gate electrode contact being in contact with the conducti
    Type: Grant
    Filed: March 22, 2010
    Date of Patent: May 29, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyasu Tanaka, Ryota Katsumata, Hideaki Aochi, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Tomoko Fujiwara, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Patent number: 8189371
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array includes a stacked body, a through-hole, a semiconductor pillar, and a charge storage film. The stacked body includes a plurality of insulating films alternately stacked with a plurality of electrode films. The through-hole is made in the stacked body to align in a stacking direction. The semiconductor pillar is buried in the through-hole. The charge storage film is provided between the electrode films and the semiconductor pillar. Memory cells are formed at each intersection between the electrode films and the semiconductor pillar.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: May 29, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryota Katsumata, Hideaki Aochi, Hiroyasu Tanaka, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Tomoko Fujiwara, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Patent number: 8178919
    Abstract: A nonvolatile semiconductor memory device, includes: a stacked structural unit including electrode films alternately stacked with inter-electrode insulating films; first and second semiconductor pillars piercing the stacked structural unit; a connection portion semiconductor layer electrically connect the first and second semiconductor pillars; a connection portion conductive layer provided to oppose the connection portion semiconductor layer; a memory layer and an inner insulating film provided between the first and semiconductor pillars and each of the electrode films, and between the connection portion conductive layer and the connection portion semiconductor layer; an outer insulating film provided between the memory layer and each of the electrode films; and a connection portion outer insulating film provided between the memory layer and the connection portion conductive layer. The connection portion outer insulating film has a film thickness thicker than a film thickness of the outer insulating film.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: May 15, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoko Fujiwara, Ryota Katsumata, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Hiroyasu Tanaka, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Hideaki Aochi, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Patent number: 8169826
    Abstract: A nonvolatile semiconductor memory device comprises: a plurality of first memory strings; a first select transistor having one end thereof connected to one end of the first memory strings; a first line commonly connected to the other end of a plurality of the first select transistors; a switch circuit having one end thereof connected to the first line; and a second line commonly connected to the other end of a plurality of the switch circuits. The switch circuit controls electrical connection between the second line and the first line.
    Type: Grant
    Filed: March 18, 2010
    Date of Patent: May 1, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoo Hishida, Yoshihisa Iwata, Megumi Ishiduki, Ryota Katsumata, Yoshiaki Fukuzumi, Masaru Kito, Masaru Kidoh, Hiroyasu Tanaka, Yosuke Komori, Junya Matsunami, Tomoko Fujiwara, Hideaki Aochi, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20120068253
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory region and a non-memory region. The memory region includes a stacked structural body, a semiconductor pillar, a memory layer, an inner insulating film and an outer insulating film. The stacked structural body includes a plurality of electrode films stacked alternately along a first direction with a plurality of inter-electrode insulating films. The semiconductor pillar pierces the stacked structural body in the first direction. The memory layer is provided between the semiconductor pillar and each of the plurality of electrode films. The inner insulating film is provided between the memory layer and the semiconductor pillar. The outer insulating film is provided between the memory layer and each of the plurality of electrode films. The non-memory region is provided with the memory region along a second direction orthogonal to the first direction. The non-memory region includes an insulating part.
    Type: Application
    Filed: March 21, 2011
    Publication date: March 22, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Shigeto Oota, Masaru Kidoh, Hideaki Aochi
  • Publication number: 20110216604
    Abstract: According to one embodiment, a method is disclosed for operating a semiconductor memory device. The semiconductor memory device includes a substrate, a stacked body, a memory film, a channel body, a select transistor, and a wiring. The method can boost a potential of the channel body by applying a first erase potential to the wiring, the select gate, and the word electrode layer. In addition, after the boosting of the potential of the channel body, with the wiring and the select gate maintained at the first erase potential, the method can decrease a potential of the word electrode layer to a second erase potential lower than the first erase potential.
    Type: Application
    Filed: March 3, 2011
    Publication date: September 8, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshimasa Mikajiri, Shigeto Oota, Masaru Kito, Ryouhei Kirisawa
  • Publication number: 20110103149
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array includes a stacked body, a through-hole, a semiconductor pillar, and a charge storage film. The stacked body includes a plurality of insulating films alternately stacked with a plurality of electrode films. The through-hole is made in the stacked body to align in a stacking direction. The semiconductor pillar is buried in the through-hole. The charge storage film is provided between the electrode films and the semiconductor pillar. Memory cells are formed at each intersection between the electrode films and the semiconductor pillar.
    Type: Application
    Filed: August 5, 2010
    Publication date: May 5, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryota KATSUMATA, Hideaki Aochi, Hiroyasu Tanaka, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Tomoko Fujiwara, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20110103153
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a substrate, a stacked body, a semiconductor pillar, a charge storage film, and a drive circuit. The stacked body is provided on the substrate. The stacked body includes a plurality of insulating films alternately stacked with a plurality of electrode films. A through-hole is made in the stacked body to align in a stacking direction. The semiconductor pillar is buried in an interior of the through-hole. The charge storage film is provided between the electrode film and the semiconductor pillar. The drive circuit supplies a potential to the electrode film. The diameter of the through-hole differs by a position in the stacking direction. The drive circuit supplies a potential to reduce a potential difference with the semiconductor pillar as a diameter of the through-hole piercing the electrode film decreases.
    Type: Application
    Filed: August 5, 2010
    Publication date: May 5, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryota KATSUMATA, Hideaki Aochi, Hiroyasu Tanaka, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Tomoko Fujiwara, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20110075481
    Abstract: A nonvolatile semiconductor memory device comprises: a bit line; a source line; a memory string having a plurality of electrically data-rewritable memory transistors connected in series; a first select transistor provided between one end of the memory string and the bit line; a second select transistor provided between the other end of the memory string and the source line; and a control circuit configured to control a read operation. A plurality of the memory strings connected to one bit line via a plurality of the first select transistors. During reading of data from a selected one of the memory strings, the control circuit renders conductive the first select transistor connected to an unselected one of the memory strings and renders non-conductive the second select transistor connected to unselected one of the memory strings.
    Type: Application
    Filed: January 27, 2010
    Publication date: March 31, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshiaki Fukuzumi, Ryota Katsumata, Masaru Kito, Masaru Kidoh, Hiroyasu Tanaka, Tomoko Fujiwara, Megumi Ishiduki, Yosuke Komori, Yoshimasa Mikajiri, Shigeto Oota, Ryouhei Kirisawa, Hideaki Aochi
  • Publication number: 20110063914
    Abstract: A nonvolatile semiconductor memory device includes: a memory unit; and a control unit. The memory unit includes: a multilayer structure including electrode films and interelectrode insulating films alternately stacked; a semiconductor pillar piercing the multilayer structure; insulating films and a memory layer provided between the electrode films and the semiconductor pillar; and a wiring connected to the semiconductor pillar. In an erase operation, the control unit performs: a first operation setting the wiring at a first potential and the electrode film at a second potential lower than the first potential during a first period; and a second operation setting the wiring at a third potential and the electrode film at a fourth potential lower than the third potential during a second period after the first operation. A length of the second period is shorter than the first period, and/or a difference between the third and fourth potentials is smaller than a difference between the first and second potentials.
    Type: Application
    Filed: March 17, 2010
    Publication date: March 17, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshimasa MIKAJIRI, Ryouhei Kirisawa, Masaru Kito, Shigeto Oota
  • Publication number: 20110049608
    Abstract: A memory string comprises: a first semiconductor layer including a columnar portion extending in a stacking direction on a substrate; a first charge storage layer surrounding the columnar portion; and a plurality of first conductive layers stacked on the substrate so as to surround the first charge storage layer. A select transistor comprises: a second semiconductor layer in contact with an upper surface of the columnar portion and extending in the stacking direction; a second charge storage layer surrounding the second semiconductor layer; and a second conductive layer deposited above the first conductive layer to surround the second charge storage layer. The second charge storage layer is formed from a layer downward of the second conductive layer to an upper end vicinity of the second conductive layer, and is not formed in a layer upward of the upper end vicinity.
    Type: Application
    Filed: March 15, 2010
    Publication date: March 3, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masaru KIDOH, Ryota Katsumata, Masaru Kito, Yoshiaki Fukuzumi, Hiroyasu Tanaka, Yosuke Komori, Megumi Ishiduki, Tomoko Fujiwara, Hideaki Aochi, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20110051527
    Abstract: A nonvolatile semiconductor memory device includes: a memory unit; and a control unit. The memory unit includes: first and second memory strings including first and second memory transistors with first and second select gates, respectively; and first and second wirings connected thereto. In a selective erase operation of a selected cell transistor of the first memory transistors, the control unit applies V1 voltage to the first wiring, applies V2 voltage lower than V1 to a selected cell gate of the selected cell transistor, applies V3 voltage not higher than V1 and higher than V2 to a non-selected cell gate of the first memory transistors, applies V1 or V4 voltage not higher than V1 and not lower than V3 to the first select gate, and applies V2 or V4 voltage higher than V2 and not higher than V3 to the second wiring or sets the second wiring in a floating state.
    Type: Application
    Filed: March 17, 2010
    Publication date: March 3, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Ryouhei Kirisawa, Masaru Kito, Shigeto Oota, Yoshimasa Mikajiri
  • Publication number: 20110031550
    Abstract: A nonvolatile semiconductor memory device includes: a stacked structural unit including a plurality of electrode films and a plurality of inter-electrode insulating films alternately stacked in a first direction; a first selection gate electrode stacked on the stacked structural unit in the first direction; a first semiconductor pillar piercing the stacked structural unit and the first selection gate electrode in the first direction; a first memory unit provided at an intersection of each of the electrode films and the first semiconductor pillar; and a first selection gate insulating film provided between the first semiconductor pillar and the first selection gate electrode, the first selection gate electrode including a first silicide layer provided on a face of the first selection gate electrode perpendicular to the first direction.
    Type: Application
    Filed: March 19, 2010
    Publication date: February 10, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yosuke Komori, Hideaki Aochi, Ryota Katsumata, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Hiroyasu Tanaka, Megumi Ishiduki, Tomoko Fujiwara, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20110018050
    Abstract: A nonvolatile semiconductor memory device, includes: a stacked structural unit including electrode films alternately stacked with inter-electrode insulating films; first and second semiconductor pillars piercing the stacked structural unit; a connection portion semiconductor layer electrically connect the first and second semiconductor pillars; a connection portion conductive layer provided to oppose the connection portion semiconductor layer; a memory layer and an inner insulating film provided between the first and semiconductor pillars and each of the electrode films, and between the connection portion conductive layer and the connection portion semiconductor layer; an outer insulating film provided between the memory layer and each of the electrode films; and a connection portion outer insulating film provided between the memory layer and the connection portion conductive layer. The connection portion outer insulating film has a film thickness thicker than a film thickness of the outer insulating film.
    Type: Application
    Filed: March 19, 2010
    Publication date: January 27, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoko FUJIWARA, Ryota Katsumata, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Hiroyasu Tanaka, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Hideaki Aochi, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20110018052
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a stacked structure, a semiconductor pillar, a memory layer and an outer insulating film. The stacked structure includes a plurality of electrode films and a plurality of interelectrode insulating films alternately stacked in a first direction. The semiconductor pillar pierces the stacked structure in the first direction. The memory layer is provided between the electrode films and the semiconductor pillar. The outer insulating film is provided between the electrode films and the memory layer. The device includes a first region and a second region. An outer diameter of the outer insulating film along a second direction perpendicular to the first direction in the first region is larger than that in the second region. A thickness of the outer insulating film along the second direction in the first region is thicker than that in the second region.
    Type: Application
    Filed: June 22, 2010
    Publication date: January 27, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoko Fujiwara, Ryota Katsumata, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Hiroyasu Tanaka, Yosuke Komori, Megumi Ishiduki, Hideaki Aochi, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20110013454
    Abstract: A nonvolatile semiconductor memory device comprises: a plurality of first memory strings; a first select transistor having one end thereof connected to one end of the first memory strings; a first line commonly connected to the other end of a plurality of the first select transistors; a switch circuit having one end thereof connected to the first line; and a second line commonly connected to the other end of a plurality of the switch circuits. The switch circuit controls electrical connection between the second line and the first line.
    Type: Application
    Filed: March 18, 2010
    Publication date: January 20, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tomoo Hishida, Yoshihisa Iwata, Megumi Ishiduki, Ryota Katsumata, Yoshiaki Fukuzumi, Masaru Kito, Masaru Kidoh, Hiroyasu Tanaka, Yosuke Komori, Junya Matsunami, Tomoko Fujiwara, Hideaki Aochi, Ryouhel Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20110002172
    Abstract: A nonvolatile semiconductor memory device includes: a memory unit; and a control unit. The memory unit includes a multilayer structure including electrode films and inter-electrode insulating films alternately stacked in a first direction; a semiconductor pillar piercing the multilayer structure in the first direction; a memory layer provided between the semiconductor pillar and the electrode films; a inner insulating film provided between the memory layer and the semiconductor pillar; a outer insulating film provided between the memory layer and the electrode films; and a wiring electrically connected to the first semiconductor pillar. In erasing operation, the control unit sets the first wiring at a first potential and sets the electrode film at a second potential lower than the first potential, and then sets the first wiring at a third potential and sets the electrode film at a fourth potential higher than the third potential.
    Type: Application
    Filed: March 22, 2010
    Publication date: January 6, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masaru KITO, Ryota Katsumata, Yoshiaki Fukuzumi, Masaru Kidoh, Hiroyasu Tanaka, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Tomoko Fujiwara, Hideaki Aochi, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota
  • Publication number: 20100327340
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a stacked structural unit, a semiconductor pillar, a memory layer, an inner insulating film, an outer insulating film and a cap insulating film. The unit includes a plurality of electrode films stacked alternately in a first direction with a plurality of inter-electrode insulating films. The pillar pierces the stacked structural unit in the first direction. The memory layer is provided between the electrode films and the semiconductor pillar. The inner insulating film is provided between the memory layer and the semiconductor pillar. The outer insulating film is provided between the memory layer and the electrode films. The cap insulating film is provided between the outer insulating film and the electrode films, and the cap insulating film has a higher relative dielectric constant than the outer insulating film.
    Type: Application
    Filed: June 23, 2010
    Publication date: December 30, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shigeto OOTA, Yoshimasa Mikajiri, Masaru Kito, Ryouhei Kirisawa
  • Publication number: 20100327339
    Abstract: A semiconductor memory device provided with a cell array section and a peripheral circuit section, the device includes: a back gate electrode; a stacked body provided on the back gate electrode; a plurality of semiconductor pillars extending in a stacking direction; connection members, each of the connection members connecting one of the semiconductor pillars to another one of the semiconductor pillars; a back-gate electrode contact applying a potential to the back gate electrode; a gate electrode provided in the peripheral circuit section; and a gate electrode contact applying a potential to the gate electrode, the back gate electrode and the gate electrode respectively including: a lower semiconductor layer; a conductive layer provided on the lower semiconductor layer; and an upper semiconductor layer provided on the conductive layer, the connection members being provided in or on the upper semiconductor layer, the back-gate electrode contact and the gate electrode contact being in contact with the conducti
    Type: Application
    Filed: March 22, 2010
    Publication date: December 30, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroyasu TANAKA, Ryota Katsumata, Hideaki Aochi, Masaru Kito, Yoshiaki Fukuzumi, Masaru Kidoh, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Tomoko Fujiwara, Ryouhei Kirisawa, Yoshimasa Mikajiri, Shigeto Oota