Patents by Inventor Ryouhei Kirisawa

Ryouhei Kirisawa 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: 8507972
    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: Grant
    Filed: June 23, 2010
    Date of Patent: August 13, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shigeto Oota, Yoshimasa Mikajiri, Masaru Kito, Ryouhei Kirisawa
  • Patent number: 8440528
    Abstract: A nonvolatile semiconductor memory device includes: forming a stacked body by alternately stacking a plurality of interlayer insulating films and a plurality of control gate electrodes; forming a through-hole extending in a stacking direction in the stacked body; etching a portion of the interlayer insulating film facing the through-hole via the through-hole to remove the portion; forming a removed portion; forming a first insulating film on inner faces of the through-hole and the portion in which the interlayer insulating films are removed; forming a floating gate electrode in the portion in which the interlayer insulating films are removed; forming a second insulating film so as to cover a portion of the floating gate electrode facing the through-hole; and burying a semiconductor pillar in the through-hole.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: May 14, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masaru Kito, Masaru Kidoh, Tomoko Fujiwara, Yosuke Komori, Megumi Ishiduki, Hiroyasu Tanaka, Yoshiaki Fukuzumi, Ryota Katsumata, Ryouhei Kirisawa, Junya Matsunami, Hideaki Aochi
  • Patent number: 8436414
    Abstract: A nonvolatile semiconductor memory device includes: a semiconductor substrate; a stacked body provided on the semiconductor substrate, the stacked body having electrode films and insulating films being alternately stacked; a first and second semiconductor pillars; and a first and second charge storage layers. The first and second semiconductor pillars are provided inside a through hole penetrating through the stacked body in a stacking direction of the stacked body. The through hole has a cross section of an oblate circle, when cutting in a direction perpendicular to the stacking direction. The first and second semiconductor pillars face each other in a major axis direction of the first oblate circle. The first and second semiconductor pillars extend in the stacking direction. The first and second charge storage layers are provided between the electrode film and the first and second semiconductor pillars, respectively.
    Type: Grant
    Filed: February 16, 2010
    Date of Patent: May 7, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyasu Tanaka, Hideaki Aochi, Ryota Katsumata, Masaru Kidoh, Masaru Kito, Yoshiaki Fukuzumi, Yosuke Komori, Megumi Ishiduki, Tomoko Fujiwara, Junya Matsunami, Ryouhei Kirisawa
  • Patent number: 8436415
    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: Grant
    Filed: March 15, 2010
    Date of Patent: May 7, 2013
    Assignee: 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
  • Patent number: 8374033
    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: Grant
    Filed: March 22, 2010
    Date of Patent: February 12, 2013
    Assignee: 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
  • Patent number: 8361862
    Abstract: A method for manufacturing a nonvolatile semiconductor memory device, the device including a stacked structural unit including a plurality of insulating films alternately stacked with a plurality of electrode films in a first direction and a semiconductor pillar piercing the stacked structural unit in the first direction, the method includes: forming a stacked unit including a core material film alternately stacked with a sacrificial film on a major surface of a substrate perpendicular to the first direction; making a trench in the stacked unit, the trench extending in the first direction and a second direction in a plane perpendicular to the first direction; filling a filling material into the trench; removing the sacrificial film to form a hollow structural unit, the hollow structural unit including a post unit supporting the core material film on the substrate, the post unit being made of the filling material; and forming the stacked structural unit by stacking one of the insulating films and one of the el
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: January 29, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Fukuzumi, Ryota Katsumata, Masaru Kito, Masaru Kidoh, Hiroyasu Tanaka, Yosuke Komori, Megumi Ishiduki, Junya Matsunami, Tomoko Fujiwara, Hideaki Aochi, Ryouhei Kirisawa
  • Patent number: 8351277
    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: Grant
    Filed: March 3, 2011
    Date of Patent: January 8, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshimasa Mikajiri, Shigeto Oota, Masaru Kito, Ryouhei Kirisawa
  • Patent number: 8320182
    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: Grant
    Filed: March 17, 2010
    Date of Patent: November 27, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryouhei Kirisawa, Masaru Kito, Shigeto Oota, Yoshimasa Mikajiri
  • Patent number: 8294191
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a first and a second stacked structure, a first and a second semiconductor pillar, a semiconductor connection portion, a first and a second connection portion conductive layer, a first and a second pillar portion memory layer, a first and a second connection portion memory layer. The first and second stacked structures include electrode films and inter-electrode insulating films alternately stacked in a first direction. The second stacked structure is adjacent to the first stacked structure. The first and second semiconductor pillars pierce the first and second stacked structures, respectively. The semiconductor connection portion connects the first and second semiconductor pillars. The first and second pillar portion memory layers are provided between the electrode films and the semiconductor pillar.
    Type: Grant
    Filed: November 10, 2010
    Date of Patent: October 23, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryota Katsumata, Hideaki Aochi, Masaru Kito, Masaru Kidoh, Ryouhei Kirisawa
  • Publication number: 20120241846
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device comprises a first conductive layer, a second conductive layer, a first inter-electrode insulating film, and a third conductive layer stacked above the first conductive layer, a memory film, a semiconductor layer, an insulating member, and a silicide layer. The memory film and the semiconductor layer is formed on the inner surface of through hole provided in the second conductive layer, the first inter-electrode insulating film, and the third conductive layer. The insulating member is buried in a slit dividing the second conductive layer, the first inter-electrode insulating film, and the third conductive layer. The silicide layer is formed on surfaces of the second conductive layer and the third conductive layer in the slit. The distance between the second conductive layer and the third conductive layer along the inner surface of the slit is longer than that of along the stacking direction.
    Type: Application
    Filed: September 18, 2011
    Publication date: September 27, 2012
    Inventors: Kaori KAWASAKI, Yoshiaki Fukuzumi, Masaru Kito, Tomoko Fujiwara, Takeshi Imamura, Ryouhei Kirisawa, Hideaki Aochi
  • Patent number: 8264031
    Abstract: A nonvolatile semiconductor memory device includes: a semiconductor substrate; a multilayer structure; a semiconductor pillar; a third insulating film; and a fourth insulating film layer. The a multilayer structure is provided on the semiconductor substrate and including a plurality of constituent multilayer bodies stacked in a first direction perpendicular to a major surface of the semiconductor substrate. Each of the plurality of constituent multilayer bodies includes an electrode film provided parallel to the major surface, a first insulating film, a charge storage layer provided between the electrode film and the first insulating film, and a second insulating film provided between the charge storage layer and the electrode film. The semiconductor pillar penetrates through the multilayer structure in the first direction. The third insulating film is provided between the semiconductor pillar and the electrode film.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: September 11, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masaru Kidoh, Hiroyasu Tanaka, Tomoko Fujiwara, Megumi Ishiduki, Yosuke Komori, Masaru Kito, Yoshiaki Fukuzumi, Ryota Katsumata, Ryouhei Kirisawa, Junya Matsunami, Hideaki Aochi
  • Patent number: 8228737
    Abstract: A nonvolatile semiconductor memory comprising: a first semiconductor layer having a first stripe-shaped region and a second stripe-shaped region which is adjacent to the first stripe-shaped region; a first NAND string formed on the first stripe-shaped region, the first NAND string having a plurality of first memory cell transistors connected in series; a first insulating film formed above the second stripe-shaped region; a second semiconductor layer formed on the first insulating film; and a second NAND string formed on the second semiconductor layer, the second NAND string having a plurality of second memory cell transistors connected in series.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: July 24, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Ryouhei Kirisawa
  • Patent number: 8218358
    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: Grant
    Filed: August 5, 2010
    Date of Patent: July 10, 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: 8199573
    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: Grant
    Filed: January 27, 2010
    Date of Patent: June 12, 2012
    Assignee: 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
  • 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
  • Publication number: 20120132981
    Abstract: According to one embodiment, a columnar semiconductor, a floating gate electrode formed on a side surface of the columnar semiconductor via a tunnel dielectric film, and a control gate electrode formed to surround the floating gate electrode via a block dielectric film are provided.
    Type: Application
    Filed: May 20, 2011
    Publication date: May 31, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takeshi Imamura, Yoshiaki Fukuzumi, Hideaki Aochi, Masaru Kito, Tomoko Fujiwara, Kaori Kawasaki, Ryouhei Kirisawa
  • 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: 8169049
    Abstract: A semiconductor device includes: a plurality of NAND memory dies each including: a first wiring layer formed in the NAND memory die; a second wiring layer formed in the NAND memory die; a first insulation layer formed between the first wiring layer and the second wiring layer; and a first interlayer connector formed in the first insulation layer, a controller configured to control the NAND memory dies; a package housing the NAND memory dies and the controller; a connecting portion electrically connecting an inner side of the package and an outer side of the package; a first connecting wire; and a second connecting wire, wherein a resistance value per unit length of the first interlayer connector is larger than a resistance value per unit length of the first wiring layer, and wherein the first interlayer connector is cut off when a first current flows through the first interlayer connector.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: May 1, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Ryouhei Kirisawa